Computers I’ve owned – Sinclair ZX Spectrum

Well it’s been 35 years since the original Sinclair ZX Spectrum was launched so i think it’s only fair to pair homage to it with my latest addition to the Computers i’ve owned section.

I’ve actually owned a few of these, albeit in there original Sinclair incarnation pre Amstrad buy out of the company in 1986 & later the +3 model.  Many people may not know this but now the Amstrad brand is now owned by Sky TV & with it they inherit all the rights to the Sinclair product line. Viglen of course absorbed the computer side of Amstrad as well, although this is it’s PC & Word processor division but i believe the Sinclair name is now still property of Sky itself as they bought out Amstrad mainly to continue development of the TV receiver boxes.

The ZX Spectrum 8-bit (Z80A) computer was released in 1982 by Sinclair Research Ltd. Originally released in 16K and also a 48K version which was the one to have.  The Spectrum evolved through a variety of versions including the Spectrum+ which added a better Sinclair QL style keyboard to the original board following criticism about the rubber key dead flesh feeling keyboard. The + model also featured a reset switch was just a push button which shorted out the circuit board to reset the machine.. basic but it did the job. Also, the 16k model wasn’t transferred with the upgraded keyboard to the Spectrum+ & killed off.  The higher spec (& now rarer) Spectrum 128 (128K RAM), the +2 with fitted tape drive), and +3 which was essentailly identical to the +2 model but came with a 3 inch Amstrad floppy drive instead. Notably, the latter two systems we created by Amstrad & not Sinclair.
The Spectrum is based on a Zilog Z80 A CPU running at 3.5 MHz. The original model had 16 KB (16×1024 bytes) of ROM and either 16 KB or 48 KB of RAM depending on which model you bought although why would you buy the 16k version?   Video is done through a built in RF Modulator – no extenal modulator to use the computer on a TV by converting a monitor output like on similar computers of the era such as the VIC20 etc.  Sound on the original Spectrum was not produced through the TV however, instead the sound was done through an internal bleeper which was basically a small mono headphone type speaker fixed to the main board although if you had the right leads & a TV with an external audio in, you could use the “Ear” port on the unit to send sound to a TV or amplifier, but would you really want to?   The “ear” port can drive headphones as we say but it’s main function was to send save files to a tape recorder and the other port for connecting a domestic tape recorder so you could load from cassette tape.

I bought my 1st spectrum when i was about 16 years old, I bought it from an old college friend for a bargain 2nd hand price of (if i remember correctly) about £35 which at the time was a weeks income to me.  It was an original 48k model with everything included, tape recorder, leads, loads & loads of games on cassette & some original Sinclair software.  I also learned a lot about computer repair from the Spectrum as i was training in electronics at the time & having took the lid off i wanted to know what each part of the computer board was doing.

Later, i then acquired an old 16k model which i upgraded to 48k by installing the additional memory chips Although as time went on the keyboard was not functional, i’d replaced the membrane (which was the common problem) but it seemed to be the plastic casing had warped not allowing for good key contact. As luck would have it i managed to pick up a Spectrum+ 48 which had a good keyboard however the main board was on it’s last legs so i transferred the upgraded 16k board into the 48k keyboard.  The last unit i acquired was an Amstrad variation.  the Spectrum +3 with working disk drive – many of the drives on +3 models were rumoured to fail quite often & it’s sometimes said because Amstrad used the better models for the CPC range or the PCW machines, alhough personally i can’t see any difference & think many of the failures were down to abuse rather than mechanical or electrical gizmo’s failing because the machines were still seen more as a toy than the other Amstrad machines.

There was also the original 128k version which i never owned, mainly as i was put off because the keyboard had a huge heatsink down the side which used to give off lots of heat.. health & safety today probably wouldn’t allow such a thing, however i bet it was nice in winter & saved on the heating bills in those cold 1980’s winters in many schoolboy’s bedrooms.

The +3 was a good machine, however i was a bit limited as i couldn’t find a lead to connect a cassette recorder so i was restricted to the disks i got with the machine & hand programming as the majoity of games etc were still on cassette & usually sold in many high street newsagents & petrol stations for just £1.99 or £2.99 by then. but with a decent keyboard & real computer feel compared to it’s predecessor, programming by hand wasn’t a problem.  Both the Spectrum +2, & +3 had two BASIC modes, the 48k BASIC to remain compatible with the original rubber keyed model & the 128k mode from the 128k with the heatsink.  The +3 however was a close cousin of the CPC464 / CPC664 & CPCP6128 especially in the way it loaded from the disk drive as the spectrum after all was designed to be only used with cassette tapes.

I later discovered that original Spectrum games could be downloaded & played on the Amstrad emailer although these days i mostly use emulation or remakes.

I really could go on for ages talking about the Spectrum & how i cut my teeth in computer repair with it, but i’ll save that for further updates.  I will howeer urge anyone into 8 bit machines to watch the Docudrama “Micro Men” which you can view here.  I will however leave you with a clip above of the programme click which sir Clive tells us how the British computer industry boomed before the market got gobbled up in the consumer world of Microsoft & the likes.



Computers I’ve owned – Amiga 500

I actually owned 2, 1 broke down & was used for parts when i obtained another one which i kept u until the late 1990s.  The Commodore’s Amiga 500 was the low-end version of the Amiga range of the time.  It was a fairly easy machine to fix & maintain as many (if not all) of the ICs (system chips) were mounted on sockets so repairs often meant removing the cover & prise out the old broken chip & replace or test with a new one.  Like the 8 bit days where the ZX Spectrum & Commodore 64 were rival machines, the main rival of the Amiga was the Atari’s 520/1040 ST range. The A500 was superior in almost every area, apart from its MIDI capabilities and the disk drive, which was not only slow but very noisy as well and a bitter feud quickly developed between owners of these rival machines.

16 bit technology overtook 8 bit tech which in the late 80’s was still very popular, but meant users had to learn a new set of skills which were closer to IBM PC use of the era as the machine used a disc loaded rather than ROM based OS which was called  Commodore’s “AmigaOS” & was essentially Kickstart firmware and the software called Workbench provided on disk. The Spectrum / CPC464 & C64 8 bit machines were still very popular as budget gaming machines with re-released or games still obtainable from many outlets for £1.99 or £2.99, some of which were ported from Arcade or 16 bit versions but of a lot lower resolution or sound & colour pallette. The A500 spec is close to the Amiga 1000, the main internal change is  in memory  256 KB to 512 KB and an additional of I/O chip that controls the disk drive and also performs some of the address decoding. This chip also featured in the A2000 which was the top of the range machine in the range from the post 8 bit era.

The A500 was an easy machine to upgrade than both the ST and oter Amigas – no more having to send the machine away for upgrades or buying newer models – as it had an expansion port located in the bottom of the case. Owners could simply insert a memory card which contained any extra RAM or add on. The popularity of this upgrade meant that more 1 MB software (both 1 MB versions of 512 KB software and 1 MB only software) was released for the Amiga than the ST, which had to be taken apart to expand the memory.  I actually discovered as well that taking the machine apart there were some additional empty IC bays to add additional memory, in fact i removed the IC’s from the add-on memory card I had & slotted them into the main motherboard, this freeing up the expansion slot. The machine also featured the Motorola 68000 processor running at just over 7MHZ on the European / UK based PAL system which is actually a 32 bit capable processor but only used 16bit addressing in the Amiga.

The A500 in my experience was ery similar to the older VIC20 i owned, whereby you could connect a dedicated monitor (which were still very expensive at the time} or connect an RF modulator to plug into the family TV or the portable in the bedroom – remember these were the days most people culd only afford to have 1 colour TV & smaller portables used in the bedroom were mostly black & white.

Although the machine was discontinued in 1991, at the time i was still using some 8 bit machines for games & such simply due to the huge catalogue & the cost of the games, although game piracy on the Amiga & Atari ST was rife with copied games being the norm for many Amiga users.. a practice almost thwarted by use of password protection such as magazine or  game manual word identity e.g “on page 12 of the manual, what is the 4th word on the 7th line”.. which was great if you owned the original but proved tricky with emulation in recent times or where you didn’t have the manual or magzine because it got lost or ruined, or even thrown away when your parents decided to tidy up.
To me the Amiga was very much a more business machine than games machine, which i used the Amiga more to do graphic creating or even basic letter writing or the like – although i didn’t have a printer so had to go with handful of disks to a mate or down the library to get stuff printed, as again, printers were an expensive add on.

The computer itself will go down as a classic & more standardised components & connections were being used. 9 pin Serial ports, parallel port, RCA audio etc in common with the IBM PC of the time.  Despite the Amiga range featuring many more desktop computers & even a games console (the CD32) including the final desktop machine, the Amiga 4000 which was probably as good as any high spec IBM PC of the mid 1990s, the A500 was probably the most popular & sadly In 1994, Commodore filed for bankruptcy and its assets were purchased by a German PC manufacturer called ESCOM, who created the subsidiary company Amiga Technologies. They in turn went bankrupt in 1997. The Amiga will have a great legacy & has been used for many things from TV graphics, creating music videos & even used by NASA during their lifetime in the computer market.

Computers I’ve owned – Binatone TV Master Mk-IV plus 2

OK not strictly a computer but a retro pong based machine & was a very popular ‘tennis’ game console from the late seventies, first manufactured in 1976 by Binatone. The Binatone  TV Master Mark IV, was one of the most popular in the UK.

tvmasterLike the dozens of other TV games that hit the shops in the 70s, it would play ‘Pong’ style games (Pong being the worlds 1st ‘popular’ arcade videogame!) made famous in the arcades and homes by Atari & such. It’s a monochrome console, since many people still owned black & white TV’s, and was cheaper to produce being based around the same AY-3-8500 (TV Game on Chip) that was used in almost every other TV game, and hence was also affordable, costing from memory about £15 to buy from new.

At the time  it was quite a futuristic looking machine as a lot of games consoles (including the Atari2600) or home technology of the time used plastic & fake wood to make them look elegant. This was very much the 1970’s version of the Xbox or Playstation if you want to enjoy video gaming as it was in the 70s, before the Atari 2600 & home computers took over.  it featured 4 different games, it has a variety of adjustment switches, such as Ball Speed, Angle & Bat Size which can alter the difficulty of the games and turn the sound off.  The paddle controllers, which consist of a simple rotary control, can be stored away in the underside battery compartment.

binatone_tv-master-4-plus-2_2The games themselves were basically all the same… the pong format with a square block – representing a ball – bouncing around the screen with a bat – which was a small solid white line – controlled by a paddle. Flicking the switch to select a different game meant that the game was changed so for example “tennis” was basically pong – with a solid white line acting as a wall top & bottom & 2 bats controlled by paddles.  “Squash” was the same game with the player 2 paddle removed & a solid wall down the right side of the screen allowing for a 1 player game or a 2 player game could be selected which added a second “bat” to the left of the screen. there was also a football game where the player controlled 2 bats simultaneously  & the side walls extended with a smaller opening. The basic gameplay remained where if the “ball” went off the screen it scored a point for your opponent. Should you get to 15 & you had to reset the game to start again with the score at 0 then try again.  The remarkable thing was there was also a lightgun available & a game called Target which was essentially clay pieon shooting where the “ball” was larger & disappeared once it registered a hit & added to the score. the same light gun was later used on some 8 bit machines albeit with a different plug attached on the end of the lead.  The target game was only featured to versions of the console known as the Plus 2 which was the system i owned.

The TV master series are first generation black & white pong consoles.  The TV Master MK IV system is the same as the Colour TV Game except that the games are in black & white, while the Colour TV game displays colour games.  The console also features a compartment underneath to store the TV cable & also the paddles could be stored inside it if the console didn’t have batteries fitted.  The machine came with a small mains adapter or could be run from if i recall 6x D sized batteries – handy if you wanted to take the console with you if you went on holiday – although if you were camping you would also need a battery operated TV – or if there wasn’t a socket spare but the battery consumption was quite high.  The paddles were quite small & basic, featuring a basic pot control to determine the position of the players “bat” on the screen & prone to failure but easily repaired using switch cleaner or replacing the pot for a better made one if you could solder the lead to it. In addition to this the supplied power supply was also prone to failure, but easily remedied as some power supplies were available (probably still are) which had a voltage selector switch & multiplug so you could power your battery run devices from the adapter if it had a socket to connect one on you battery operated device.

You may think being old you’d need an old TV or bespoke monitor to play on one today, however like most games machines of the time & during the 80’s it connected to the TV via the RF cable or ariel input & then was a case of tuning a spare channel to the console  as you would if you tuned in a new TV station. usually it was around the 35mhz mark later used by Channel 5 & what many home consoles & Video recorders were set to which was around the middle of the tuning dial.  if you have a modern TV, simply set the TV on analogue input & the switch on the console & tune in the TV but don’t worry, gaming in black & white was normal & you could always turn the TV sound off as it came from a bleeper on the console itself & played through a speaker on the console, again this could be turned off by a selector switch on the machine as the beeps got annoying after a couple of rounds of tennis.


Interview with Christopher Curry

Scouring Youtube the other day, i stumbled across this Interview with Chris Curry, the founder of Acorn Computers.

Computers I’ve Owned – Amstrad PCW

The Amstrad PCW. I know what you are saying “they are not computers but basic word processors” to which you have a point, however the PCW series machines i owned (as detailed here) were able to be loaded into DOS or CP/M type modes, allowing the use of bespoke software to be loaded so basic programs could be loaded.

I had 2 of these machines, let’s start with the 1st.

Amstrad PCW-9512 The 1st machine i owned was the PCW 9512.  I acquired the machine in the early 90’s, given to me by someone who had no use for it as they had bought a PC from work & I kept the machine until it gave up the ghost a 6 or 7 years later.  I got the machine given to me so didn’t really have a lot with it, so no box, no manual etc but i had the software that came bundled with the machine on disks but that was about it, other than the monitor which housed the electronics (motherboard, CRT, floppy, power supply) & the bespoke keyboard that plugged into the front.  I didn’t have the original Amstrad PCW daisy-wheel printer that originally came packaged with the machine (shown in the image), but had to use an old Citizen 120e swift dot matrix printer, which i bought cheap from a local second hand shop & actually worked well with the machine & hooked quite easily to the parallel port on the back of the machine, so much so i had to replace the ribbon twice as i did so much on this machine!

The PCW 9512, was 1st introduced in 1987 & the bigger brother of the 8512 & the 9256, this model unlike earlier models which used green-screen discplays had a white-on-black screen instead of green-on-black,  The software supplied with the machine was the more advanced version 2 of the Amstrad Locoscript word processor program which included spellchecker and mail merge facilities & was on similar lines to Wordstar & copied elements from Word Perfect which at the time of the later half of the 1980’s were the “Microsoft office” products of the day.  The original machine had the Amstrad 3 inch drive as used in the CPC664 / 6128. ZX Spectrum +3 & the older Amstrad word processors which did cause a few problems.  As i already had used word processing programmes such as Word Perfect & Wordstar & used CP/M, along with a couple of hours use of the PCW 8256 at a technical college i used to study at, I picked up the basic of operating the machine quite easily & it almost seemed 2nd nature, so the lack of a manual or having to trek to the library (no broadband internet in those days) to study a manual & photocopy critical pages from wasn’t an issue.  I taught myself much of the other features of the software as well as what the disk had, Also included with the machine on the floppy disks was a simple version of BASIC as a loadable program, so days of reliving with simple programming such as 10 PRINT “HELLO “; 20 GOTO 10 was a nice touch of retro computing, but making up games or making the computer play a tune were not to be.Amstrad-floppy

As the Amstrad disks got rare & damaged i heard about a mod for the machine to convert the system to 3½-inch standard floppy drive either, by using the 2nd bay (which was blanked off) or by replacement of the entire drive which i attempted both methods, however i think the drive i used wasn’t compatible & it was a failed project, which was a shame as i would of like to of saved some of my files & still been able to use some of the templates on later machines.  the later released PCW 9512+, was equipped with a single 3½-inch disk drive that could access 720 KB. The 9512+ was basically the same machine with just the use of the drive changed & the ability to use inkjet printers.

My machine was used on a regular basis for all sort of things like applying for jobs, writing CV’s etc & even some college projects which i had to do at home as the college computers were PC systems, although my 1st experience with PCW machines came earlier as i was at a training centre where in the other class rooms they used to teach office skills on the 8256 machines to students & i used them a few times & on occasion had to do basic repairs on them.  All the PCW systems used the Zilog Z80 processor & the memory was basically given away in the name, 512 or 256k options depending on the machine you owned.  The PCW never really had an impact on the computer market as it was after all not a computer in the conventional sense.. the IBM PC was very much the machine of the day for computing & the 16 bit market was in it’s infancy so at the time the days for the old 8-bit games machines or home computers (such as the Spectrum, Commodore, Amstrad CPC etc were already numbered but with costs of up to £1000 for an IBM PC system of the time back in the late 1980’s an affordable under £500 PCW seemed a good option if you just wanted a system for home word processing & not much else.

Eventually my machine died a death when the CPU gave up the ghost, for some strange reason though the CPU in my machine was board mounted & not mounted in an IC cradle & the processor slotting into that to allow for easy replacement like most CPU’s in those days, so although i tried to replace my processor, doing so would of damaged the PCB so eventually the machine had to be scrapped.

After the demise of the earlier PCW machine i tried to get a replacement machine,  if only to keep using my old files so i wouldn’t have to replace them or start again.  Sadly i couldn’t find another machine so took the chance on an upgrade to the newest PCW machine, the Amstrad PcW16

Amstrad PCW16I spotted this PCW for sale in Dixons for about £140 at the tail end of 1996 & thought i would take the plunge, obviously this was a lot lower price than 1st advertised of £290 when the machine was in there 12 months previously & i’m guessing Dixons had a load in stock they wanted rid of, so i took the plunge.  The machine impressed a few of my friends who liked the idea of a computer for £140, but the story isn’t quite so straight forward.  yes for the £140 i got the CRT monitor which like it’s predecessor was a black/white mono display which also housed the electronics for the machine, which the keyboard plugged into. the Keyboard was included & as was a mouse, but this time unlike previous models this was an IBM type PC keyboard & it had a serial mouse.   As with previous models software was included, but this time stored onto a flash drive within the machine so you didn’t have to load up the software to boot the machine before you could use it. Sounds good.. the 1st problem then came as i had the dot matrix from the older machine i assumed it still would work in this machine, so plugged the printer in & it did nothing only spat paper out for 20 minutes before i realised something wasn’t right.  Upon reading the manual (yes i am a bloke i don’t read manuals 1st like they suggest) i discovered this machine was compatible with only a few printers.. mostly expensive bubble jet machines, so £140 for the machine & the printer they recommend if you go to the one at the top of the list was a £600 high-end office printer, not so cheap this “cheap” computer that impressed my friends so far. Upon further inspection i discovered the Canon Bubble-jet series printers were on the list & the cheapest the BJC250 which also had the advantage of as the PCW was a mono / text printer, no need for expensive colour cartridges & a simple black only one was available, so off i went to PC world to get one along with another £150 kick in the wallet to get a BJC250.  However there is a funny story attached to when i went to buy the printer & the salesman offered me a Lexmark printer for £100 & insisted it would work with my machine, to which i said “can i bring it back & have the canon if this won’t work on my machine for the same money” & even got the manager to sign it in writing , so confident was the salesman this printer would work.. it didn’t so i returned it & got the £150 printer for £100.. less the cost of the call to Lexmark tech support on their premium tech support number to get them to confirm that this printer only worked with Windows systems & not the Rosanne GUI system included on the PCW of course, i was up about £45 on the deal, plus my Canon had both colour & mono carts in the box.. result.  However this lead to a sub-problem of slow printing which is probably why they were keen to say the machine liked the more expensive office printers rather than the good old fashioned low cost home variety.
Problem 2 was the drive, of course the older machine used Amsoft 3 inch compact drives where the PCW 16 which would read & import “some” older PCW files now (as the machines software systems were not fully compatible) it had a standard floppy drive installed. An upgrade pack for the machine so you could buy an Amsoft drive & connect it to the PCW was available.. at a cost of £120, which considering i was paying £5 a time for PC floppy drives at the time was a kick in the wallet, so i decided to abandon the idea of transferring my files from the 9512.
The PCW 16 is an upgrade to the PCW 10 model, which was an update of the previous 9512 system & labelled it as “PcW” instead of “PCW”,  it had its own bespoke GUI operating system, known as “Roseanne”. (hence why it wasn’t able to recognise Lexmark printers) which was an almost Windows 95 like system compared to the more CP/M system on the older models which i can best describe as a cross between Amiga Workbench & Windows 3.1 & ran one application at a time so no multi-tasking as you could with a Windows system.  The software included an updated Locosoft word processor package similar to their PC package, but also had spreadsheet software, address book for your contacts, an events diary, a basic calculator and even a Windows 3.1 type file manager.  There was also an easter egg on the included floppy drive (which was a back-up copy of the installed software) which if you typed in a word or a string of letters it would process the word & use the spell checker to find words in what you had typed.. very handy if you worked on Channel 4’s “Countdown” in dictionary corner, although it took more than 30 seconds for it to find a 3 letter word most times.

The display was a fairly  standard VGA 640×480 display but the words were clear on the screen & this time white-on-black.  As i said the  PcW16 used a flash memory (as opposed to a HDD) to store the GUI operating system & some files could be saved on it in the space that was left, but it was always handy to keep a floppy in the drive to save files on rather than using the internal memory other than for temp files, & the files were so small you could fit hundreds on the floppy & i never came close to filling just 1 disk with almost everything i ever did on the machine, so it must of used some really clever compression or stored the files in a small format.  the PcW16 used the 8-bit Zilog Z-80 CPU, but that seemed about it as the machine was completely different to it’s previous models on hardware, on everything else, although the spec list was similar to the 9512, although the machine could connect to the internet (again using very expensive hardware to do it, so cheaper to buy a Windows PC), plus you were limited to text only websites.
I had some concerns about the machine so wrote to Amstrad using the address in the manual.  I explained i know this machine is NOT a PC or intended as a PC system in any way, but if the hardware packed up, would i be able to use standard PC hardware (considering i had issues trying to install a standard floppy in the 9512 as a 2nd drive) among a few other technical issues. After about a month  i got a reply back from Viglen who had obviously acquired the Amstrad computing brand by that time, to say the keyboard was a fairly standard PC compatible keyboard, the mouse was able to use a standard serial mouse, but if not a simple wiring change was required – which i remember from using mouse ports on some older 8 bit machines, so all good so far. I was also told the machine was slow at printing because what the print function did was basically emulate the text into a graphic format & print the document as a graphic, so if you can imagine creating a document in MS word, then taking an A4 bitmap image of your document & then printing out the bitmap.  That explains why they liked expensive printers in the manual & the list of machines, why printing was slow & why the dot matrix printer wouldn’t work.  On the plus side, the files could be exported to PC as files could be saved / converted to .txt files. so formatting was an issue, but at least it meant an upgrade was possible without losing my older precious files all over again or having to start making templates as a few clicks of the mouse & you could get the formatting back to where you were before.

Even so this machine served me well for the couple of years i owned it, the machine sadly is no longer with us & is currently listed as “missing”. i bought a newer PC after owning the machine for a couple of years, so Windows 98 & MS Office 97 was around by then so the PCW series became a little surplus to requirements. I put the PcW machine to one side & i think my dad ended up giving it to someone else (most likely one of my friends who was impressed with my £140 computer) or probably just skipping the machine assuming it didn’t work, but at least i managed to keep the printer back for my PC & that colour cartridge i never needed to use eventually came in handy.  Even so, i think as a system it had promise, i often think i could of used this machine to teach the kids word processing & of course not have to worry about them installing viruses & malware on the PC from software borrowed from their mates or playing games while doing their homework, so if i had the machine today i would let the kids use it to do their homework & learn the basics of spreadsheets & working on word documents, before graduating them onto a PC with office software installed.  Even before the days i had laptops etc, this machine (as was it’s 1st incarnation) was easy enough to package up & take with you to a friends house or even a hotel if you wanted to catch up on your letter writing or continue working as it just needed a keyboard plugging in to the monitor case & plugging into the mains, so in some ways a very portable system.