The Bi-Weekly British Backtrack - The Amstrad CPC Computers
by, 09-30-2010 at 02:21 PM (2159 Views)
This column seems to come around more quickly each time, it seems like just a couple of weeks ago when I last. ...... oh.....
Anyway, we're back to the UK hardware again, and we'll take a look at both the company and the product too. Specifically we'll look at the range of Amstrad CPC computers, but first we'll look at how they came to be.
Amstrad was founded in 1968 by Alan Sugar and the company name is derived from his own name (Alan M Sugar Trading) the M standing for Michael. As a side note, following the success of the US version of the TV show The Apprentice, the UK had their own version featuring the by now Sir Alan Sugar.
Amstrad first entered the market in consumer electronics and had some success in the 1970s where they were quite prolific in producing low priced Hi-Fi equipment, TVs and Car Audio systems, back then using cassettes obviously. They managed to undercut the market by using a different manufacturing process to their competitors rather than saving costs by using cheaper components. Amstrad used injection moulding rather than vacuum forming like their competitors did.
In 1980 Amstrad went public and traded on the London Stock Exchange and following that brave move they doubled in size every year throughout the 80s and eventually got into the now booming home computer market, following Commodore and Sinclair's leads and in 1984 they released the Amstrad CPC range.
The CPC 464 was launched in the UK, France, Australia, New Zealand, Germany, Spain and Italy and it was eventually followed by the CPC 664 and CPC 6128 and later plus models of the 464 and 6128 came out in 1990 with small upgrades including the addition of a cartridge slot, upgrades to the video display that increased the colour palette to 4096 colours and the facility for hardware sprites. The sound system in the plus models was improved as well, even though the actual sound chip itself was unchanged, it was given an automatic DMA transfer system so it could communicate directly rather than using up valuable CPU time.
In 1985, they released the very popular Amstrad CPW range which were a group of word processors that came with a printer and ran the program LocoScript but they could also run the full CP/M as well if you loaded it through the floppy drive. Weve actually got a CPW sat in a science cupboard at work and one day I plan to liberate it and try to get it up and running, the same way I did with the Commodore PET I found in a similar cupboard. The main problem getting a CPW running nowadays is replacing the belt in the floppy drives which were notoriously bad and fail quite often, particularly after sitting in science cupboards for 25 years. To provide software and consumables for the CPWs Amstrad created a division of the company called Amsoft.
In a monumental announcement on April 7th 1986 Amstrad announced that it had bought from Sinclair Research for £5million, and I quote, "...the worldwide rights to sell and manufacture all existing and future Sinclair computers and computer products, together with the Sinclair brand name and those intellectual property rights where they relate to computers and computer related products." which obviously included the huge selling ZX Spectrum. It also included all of the unsold stock of Sinclair QLs and Spectrums which made Amstrad well over £5million alone.
The next Sinclair Spectrum machines to be released were obviously made under the mantle of Amstrad and they launched two new versions, the ZX Spectrum +2 (which was essentially a ZX Spectrum 128 with a built-in tape drive like the Amstrad CPC 464 had, and the ZX Spectrum +3 with a built-in floppy disk drive like the Amstrad CPC 664 and 6128 had, but these systems had to compete with the higher specification 16bit Atari ST and Commodore Amigas and eventually lost out to both.
In 1986 Amstrad produced a range of PCs that were initially MS-DOS based and then later Windows based, and the first of these was the PC1512 that was priced at again a very competitive £399 and it went on to gain more than a foothold in the market by capturing more than 25% of European computer sales, and they tried in vain to repeat that success in the portable computer market in 1988 with the PPC512 and 640 models that were based on an 8MHz processor and ran MS-DOS.
The next generation of Amstrad PCs failed to achieve the success that the PC1512 had enjoyed, mainly due to bad press and a product recall. The 1989 PC2000 series were fitted with Seagate ST277R hard drives but because of hardware issues with them, the computers had to be recalled and were fitted with Western Digital drives instead, but the bad press among other things meant that they lost momentum and lost their market lead in Europe.
Having lost this lead the company turned their attention to the game console market and in 1990 they released the Amstrad GX4000 which was a console based on the Amstrad 464 Plus hardware. Unfortunately the system was 8bit in what was fast becoming a 16bit era and was dominated by the Sega Mega Drive and Super Nintendo.
Amstrad, and Alan Sugar in particular, have never been willing to throw in the towel too easily and in 1993 they were licenced by Sega to produce a system similar to the Sega TeraDrive that was named the Amstrad Mega PC. Unfortunately the initial retail price of £599 killed it before it had a chance to survive, but learning from this mistake they released their Apple Newton rival, the Amstrad PenPad, which was cheaper than the Newton at $450 to the Newton's $800 but sadly it was a sub par product with technical issues and it lacked some of the Newton's features.
Amstrad now switched tack and began to focus on communications after buying out a few comms companies including Betacom, Telecom, Viglen Computers and Dataflex Design Communications, and Alan Sugar again demonstrated his understanding of the industry and his business acumen by branching out into other markets as he had been continually manufacturing set top boxes for the UK satellite TV provider Sky, and in fact at Sky's UK launch Amstrad were the only company producing the set top boxes and satellite dishes, and they've continued in that field to produce newer boxes moving with Sky from Analog to Digital and now to Sky+ which is a satellite digital video recording system.
In 1997 Amstrad PLC was wound up and its shares split into Viglen and Betacom with Betacom PLC being renamed to Amstrad PLC, and their biggest inventions of more recent times again failed to achieve the huge success that was hoped for but they do still exist and they are range of telephones known as the Amstrad E-m@iler and which combined telephone functionality with email. The first model arrived in 2000 and the E-m@iler Plus arrived in 2002 before the E3 Videophone in 2004.
So, returning to the CPC 464 then, it was introduced in 1984 as a direct competitor to the Commodore 64 but it was packaged as a "complete system" because it came with its own monitor and built-in cassette deck. The original CPC range was successful, especially in Europe selling 3 million units.
Spec wise the system;
Ran from 1984 to 1990
Was based on a Zilog Z80 CPU at 4 MHz
Had 64 kb RAM with 42kb left for users
Had 16kb of VRAM and 32kb of ROM
Text modes supported displays of;
o 20 x 25 with 16 colors
o 40 x 25 with 4 colors
o 80 x 25 with 2 colors
Graphic Modes supported displays of;
o 160 x 200 with 16 colors
o 320 x 200 with 4 colors
o 640 x 200 with 2 colors
Supported up to 27 colours
Had a full QWERTY mechanical keyboard with numeric keypad and edit block
3 sound channels with 8 octaves +1 noise channel
Atari standard Joystick port
Floppy Disc Port
DIN plug for Amstrad monitor
Stereo jack output
Built in cassette tape recorder
Came with built in Locomotive Basic
So, it was 8bit and like I said ran on a Zilog Z80 processor clocked at 4 MHz but interestingly it had originally been built as a prototype machine using a 6502 but was changed late in the game to the Z80.
The standard 9 pin joystick port with the pin layout the same as a standard Atari joystick port so you could use your existing joysticks or contemporary joysticks, but you needed a splitter to connect more than 1.
The video output was through a Motorola 6845 address generator connected to a pixel generator that supported 4, 2 and 1 bits per pixel, and the three built-in resolutions were available but you could increase screen size by reprogramming the 6845. A colour palette of 27 colors was supported but as I said, the later Plus range upped that to a palette of 4096 colours and added support for hardware sprites.
It had no RF TV or composite video output and used a proprietary 6-pin DIN connector that was for use only with Amstrad monitor. Of course you could buy an external adapter that connected to RF to use with a TV and even a SCART cable if it was wired properly, and of course it gave out a PAL signal.
The sound chip was a General Instrument AY-3-8912 sound chip with 3 channels, and it worked in either mono using the built in speaker or stereo through the 3.5 mm headphone jack
The hardware and the firmware were designed so they could access software in external ROMs, and these ROMs had to be a 16k block that was switched in and out of the memory space shared with the video RAM, and that was done deliberately so new software could be released and accessed from the ROMs. Most of them were packages for things like word processing. Now, the ROMs didn't plug directly into the computer itself, they used something called "rom-boxes" which acted like an adaptor and contained sockets for the ROM chips along with some decoding circuitry for the main machine to be able to switch between them. These boxes were either marketed commercially or they could also be built by hobbyists and they would attach to the main expansion port at the back.
The obvious advantage of these ROM chips over something like disc or tape is that they load much faster, and anyone who used a game cartridge on the Commodore 64 will know, you boot that up and the game is right there, as opposed to loading it from the 1541.
Also the CPC's boot sequence was designed to evaluate any ROMs it found and optionally hand over control of the machine to them. The funny thing was that the typical CPC user would have no idea about this added ROM functionality because it wasn't mentioned in either the user manual or usually in marketing campaigns either, but it was in the official Amstrad firmware manual, and back in the 80s we all read that didn't we?
Like I mentioned, the CPC664 used a 3inch floppy drive and they chose to use the Hitachi 3" floppy when just about everybody else was switching to the Sony 3.5" drive, allegedly because Amstrad had sourced a huge bulk order of the 3 inch drives from a supplier in Asia. The drive was single-sided, had 40-tracks and the user had to physically take the disk out and flip it over to use both sides, so each side had its own write-protect switch and they were labelled A and B with each one formattable to 180 kB (in AMSDOS format) made up of a 2 kB directory and 178 kB for storage, obviously a total of 360 kB per disc.
Because the discs didn't use the same sliding metal protection cover to protect the disc surface, it used an internal cover which made the discs much more expensive to manufacture, and as the market was moving to the 3 and a half inch format which had more storage capacity into the bargain, the format died shortly after the CPC itself died.
A saving grace perhaps was that an interface meant that the CPCs could actually use a standard 3", 3½" or 5Ό" drive as their second drive, and programs such as ROMDOS and ParaDOS extended the standard AMSDOS system to provide support for double-sided, 80-track formats so the CPC could actually store 800kB on a single floppy disk after all.
Also at the back of the machine were 2 serial interfaces, with a through-connector for the CPC464 disk drive or other peripherals, and the interface could also transfer data between other systems including British Telecom's Prestel service that I covered in show 2 back in March 2009. A funny side note to that feature is that Amstrad made a second version of the ROM for the U.S. Market because the original used the commands "SUCK" and "BLOW" which were said to be unacceptable stateside.
So, moving from the hardware to the software, like most 1980s home computers the CPC had its OS and a BASIC interpreter built into a ROM chip, and it used Locomotive BASIC which was actually an improved version of the Z80 BASIC that the BBC Microcomputer used, as I covered in show 7 in August 2009. The main advantages of using this version of BASIC was that it was more efficient than the common Microsoft BASIC used by the Commodore 64 when it was communicating with the audio and video hardware, because the Commodore 64 had to use POKE commands instead. It also allowed timed event commands to be used such as the AFTER and EVERY command so you could force an event to happen at a specific time in your program. Unfortunately, unlike the BBC Micro Locomotive BASIC could not combine BASIC and assembly language.
As I said, the later 664 and 6128 came supplied with CP/M and that opened up the machine to the abundance of Public Domain software out there.
The CPC range had quite a long lifetime and developed a strong and dedicated community, and I think that's mainly because it was also a business machine. If you think back to my segment on the BBC Micros, they mainly succeeded because they were adopted by the education establishment which put them into every school and a lot of businesses, and the Amstrad was lucky in that it became a business machine which helped prolong its life and increase its sales figures.
This community thrived and programmers even went as far as developing GUI based Operating Systems like FutureOS and SymbOS, and the gaming community among other things produced Amstrad magazines such as Amstrad Action, Amtix!, CPC Attack and Amstar. That kind of mirrors its market rivals at the time too, the ZX Spectrum and the Commodore 64, and that's how I remember it back then too. The 3 systems were all contemporaries and fought it out for the gaming community's money. They each had games, many of them ported across all 3 systems, they all had magazines devoted to them and they all started playground arguments and fights. In fact Retro Gamer magazine to this day has a feature where they compare a game across the 3 systems and give results based on the Graphics, Sound and Gameplay.
Interestingly, and not that commonly, following the CPCs end of production, Amstrad gave permission for the CPC ROMs to be distributed freely as long as the copyright message isn't changed, and that it's always acknowledged that Amstrad still holds the copyright, so that means that emulator developers can legally ship the CPC firmware with their emulator, and there are a few good ones out there
The most common is probably WinApe from winape.net that emulates all CPC models on Windows 95/98/Me/NT/2000 and XP but there are emulators for other platforms such as Arnimedes that has both Windows and DOS versions but there are also good emulators for Linux, Macintosh, Nintendo DS, PSP, Wii, GP2X and Java
Games wise, the Amstrad CPC464 has great versions of games including
Way Of The Exploding Fist
and lots of others too, but one thing that used to strike me when I played on the CPC464 was that the colours were too much, they seemed to make it hard to discern detail sometimes. It was as though the developers just discovered they had colour, and used it everywhere.
Whether that is real or imagined I don't know, but it sticks in my mind, in particular a game like Flimbo's Quest which on the Commodore 64 and Amiga had quite detailed environments and lots of shading on the rocks and trees, and on the 64 they were nice, but on the Amstrad, it seemed to be a bit OTT, you know as though theyd shaded areas without the real need to, just because they could, or because they had RAM left or something.
It's hard to explain but imagine Da Vinci looking at the Mona Lisa and saying Right, it's finished, but I've got all this paint left. I'll put some here, some here, and I'll go over this bit again.
Does that make sense? Anyway, try it and see for yourself. See what you think and let us know in the forums as always, and do your own game comparisons, try a game on the Spectrum, the Commodore and the Amstrad and see which you prefer.
If you don't own the hardware you can find some further info and some emulation options here;