AndrewMuller wrote:
As the world is seeks energy independence, the usage of renewable, sustainable energy resources has risen. The renewable energy can act as a principal or alternate source of power generation. It is a common source of energy in rural areas where transmission and distribution of other sou
Hello Andy me old mucker. Did I tell you I like Amstrads as much as you like wind? I'll fill you in.....
Amstrad launched their first home computer in April 1984. It was the CPC 464 and had 64k of RAM and a built in cassette recorder. The machine included one of the best home versions of BASIC of the day which was supplied by Locomotive. Many regard it as the ultimate 8 bit BASIC interpreter because it built upon standards set in the popular BBC BASIC from a year earlier.
The CPC's processor was the popular Z80a from Zilog. It was a 4MHz CPU, although in reality the CPC clocked in at about 3.3Mhz. The machine could display 16 colours from a pallette of 27, putting it ahead of the Spectrum and Commodore 64 for graphics.
One of the major bones of contention with the machine was that it had no RF or composite output and was sold only with a monitor. The reasoning behind this was that Alan Sugar wanted to sell an "all in one" solution. So the monitor came bundled with the machine. However this gave the advantage that the display was far higher quality than most other home computers of the day because it was fed with an RGB connection whereas the Spectrum and C64 were stuck with RF or composite PAL.
The CPC was a great success and therefore Amstrad opted to launch a disk based model, the 664. Shortly after their launched a 128k disk model in America only. But thanks to reduction in the price of RAM the 6128 was soon introduced to the UK market superseding the 664. This annoyed many 664 owners who had only had their machines for 6 months or less!
In 1990 the machines were updated to reflect the changing computer market. A 4096 colour palette was added as was sprite handling abilities. However this was initially restricted to games that used the new cartridge port.
Of course the CPC wasn't the only computer Amstrad made, far from it. The Amstrad PCW series was a range of personal computers produced
from 1985 to 1998, and also sold under licence in Europe as the "Joyce" by the German electronics company Schneide. When it was launched, the cost of a PCW system was under 25% of the cost of almost all IBM-compatible PC systems in the UK. As a result PCWs became very popular in the home and small office markets, both in the UK and in Europe, and persuaded many technophobes to venture into using computers.
Unusually the monitor casing included the CPU, RAM, floppy disk drives and power supply for all of the systems' components. All except the last included a printer in the price. Early models used 3-inch floppy disks, while those sold from 1991 onwards used 3½-inch floppies, which became the industry standard around the time the PCW series was launched. A variety of inexpensive products and services were launched to copy 3-inch floppies to the 3½-inch format so that data could be transferred to other machines.
Like the CPC the PCW used the Z80 processor which could only access 64 KB of RAM at a time. Software could work round this by bank switching, accessing different banks of memory at different times, but this made programming more complex and slowed systems down. The PCW's CP/M applications could not use more than 64 KB, and the system used the rest of the RAM as a RAM drive. On the other hand the standalone Locoscript word processor program was reported as using up to 154 KB as normal memory, and the rest as a RAM disk.
All models barring the last included the Locoscript word processing program, the CP/M Plus operating system, Mallard BASIC and the LOGO programming language at no extra cost. A wide range of other CP/M office software and several games became available, some commercially produced and some free. Although Amstrad supplied all but the last model as text based systems, graphical user interface peripherals and the supporting software also became available. The last model had its own unique GUI operating system.
The PCW having a 2 colour display designed for text only might not have made it ideal for games, but some companies managed it! Games like Batman, Head Over Heels, and Bounder were released across the machines life.
In order that it be able to display a full 80 column page plus margins, the display's addressable area was 90 columns and the display had 32 lines. The display was, in fact, monochrome and bitmapped, giving a resolution of 720 by 256. Even with one bit per pixel, this occupied 23 kB of RAM, making software scrolling far too slow for fluid text manipulation. In order to improve this, the PCW implemented roller RAM, with a 512-byte area of RAM used to hold the address of each line of display data, effectively allowing very rapid scrolling. The video system also fetched data in a special order designed so that plotting a character eight scan lines high would touch eight contiguous addresses. This meant that very fast Z80 copy instructions like LDIR could be used. Unfortunately, it meant that drawing lines and other shapes could be very complicated.
And then of course there is the Amstrad PC's, fantastic low costs PC's that grabbed a huge share of the IBM compatable market in the mid 1980's. I've probably been going on for a bit so I won't put details here. But rest assured Andy, you can just PM me and I'll personally fill you in. Perhaps we could hook up and you could arrange for some wind power to supply my Amstrad machine. I think that would be jolly good fun.