Difference between revisions of "472"
From CPCWiki - THE Amstrad CPC encyclopedia!
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The reason [[Amstrad|Amstrad]] released a special version for the spanish market was a law ([[RD 1250/1985|RD 1250/1985]]) that said that every computer with up to 64kb should adhere to some rules - namely, have extra keys for the spanish language, and the video hardware had to be able to display spanish characters; otherwise an extra tax would be levied. So Amstrad soldered in an extra 8kb which was not, however, usable by the machine since it was not connected to anything else. Later on Amstrad released a 472 with a proper spanish keyboard and the 8 extra kB as well. [[Image:Amstrad 472 motherboard.jpg|thumb|right|200px|Left side of the CPC472 motherboard, revealing the location for the presumely 8KB expansion memory.]] | The reason [[Amstrad|Amstrad]] released a special version for the spanish market was a law ([[RD 1250/1985|RD 1250/1985]]) that said that every computer with up to 64kb should adhere to some rules - namely, have extra keys for the spanish language, and the video hardware had to be able to display spanish characters; otherwise an extra tax would be levied. So Amstrad soldered in an extra 8kb which was not, however, usable by the machine since it was not connected to anything else. Later on Amstrad released a 472 with a proper spanish keyboard and the 8 extra kB as well. [[Image:Amstrad 472 motherboard.jpg|thumb|right|200px|Left side of the CPC472 motherboard, revealing the location for the presumely 8KB expansion memory.]] | ||
| − | The 8KB "extra" memory, was in fact a single [[4164|4164]] DRAM chip. | + | The 8KB "extra" memory, was in fact a single [[4164|4164]] DRAM chip (64Kx1bit). |
Because there was no space for a new chip, Amstrad designers took off one of the ROM chips, and put it in a daughter board, along with the 4164 chip. Wires connected pins at the ROM from the daughter board to the corresponding pins on the main board. The wires were hard enough to make difficult to turn the daughter board over and reveal the trick: no wires were connected from the DRAM chip to the main board. Even the supply pins were not connected!! | Because there was no space for a new chip, Amstrad designers took off one of the ROM chips, and put it in a daughter board, along with the 4164 chip. Wires connected pins at the ROM from the daughter board to the corresponding pins on the main board. The wires were hard enough to make difficult to turn the daughter board over and reveal the trick: no wires were connected from the DRAM chip to the main board. Even the supply pins were not connected!! | ||
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While based on the CPC 464, at least some of the 472s got the ROM v2 with [[Locomotive BASIC]] 1.1, which normally was built into the CPC [[664]]. | While based on the CPC 464, at least some of the 472s got the ROM v2 with [[Locomotive BASIC]] 1.1, which normally was built into the CPC [[664]]. | ||
| − | After the rule changed there was also a CPC 472 with | + | After the rule changed there was also a CPC 472 with spanish keys and BASIC 1.0 available for a very short time. |
| + | |||
| + | The CPC 472 with spanish or british keyboard is very very rare.[[Image:Amstrad 472 detail motherboard.jpg|thumb|right|200px|Motherboard close-up, showing the "8KB" extra memory, next to the 40037 ROM chip.]] | ||
| + | |||
| + | In some interviews, Amstrad developers stated that they have never heard of the CPC472, so it's possible that the daughterboard was made by Indescompt (the spanish distributor), not by Amstrad. | ||
[[Category:Hardware]][[Category:CPC History]][[Category:CPC Internal Components]] | [[Category:Hardware]][[Category:CPC History]][[Category:CPC Internal Components]] | ||
Revision as of 19:24, 5 April 2010
The CPC 472 was a spanish version of the CPC 464 with additional 8 KB RAM. The reason Amstrad released a special version for the spanish market was a law (RD 1250/1985) that said that every computer with up to 64kb should adhere to some rules - namely, have extra keys for the spanish language, and the video hardware had to be able to display spanish characters; otherwise an extra tax would be levied. So Amstrad soldered in an extra 8kb which was not, however, usable by the machine since it was not connected to anything else. Later on Amstrad released a 472 with a proper spanish keyboard and the 8 extra kB as well.
The 8KB "extra" memory, was in fact a single 4164 DRAM chip (64Kx1bit).
Because there was no space for a new chip, Amstrad designers took off one of the ROM chips, and put it in a daughter board, along with the 4164 chip. Wires connected pins at the ROM from the daughter board to the corresponding pins on the main board. The wires were hard enough to make difficult to turn the daughter board over and reveal the trick: no wires were connected from the DRAM chip to the main board. Even the supply pins were not connected!!
While based on the CPC 464, at least some of the 472s got the ROM v2 with Locomotive BASIC 1.1, which normally was built into the CPC 664.
After the rule changed there was also a CPC 472 with spanish keys and BASIC 1.0 available for a very short time.
The CPC 472 with spanish or british keyboard is very very rare.
In some interviews, Amstrad developers stated that they have never heard of the CPC472, so it's possible that the daughterboard was made by Indescompt (the spanish distributor), not by Amstrad.
