Started by Liartes, 12:09, 28 August 20
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Quote from: Liartes on 18:01, 28 August 20Surprise under the heatsink: The GateArray is a 40008 socketed on the 40007 slot, as documented here https://cpcrulez.fr/codingBOOK_weka_02322.htm this version is not pin compatible with the 40007. does a 40008 would work in the 40010 slot then ?
Quote from: Liartes on 19:27, 28 August 20Edit 2: GA 40008 is working fine on another motherboard. I am back to the suspicious transistor, waiting for supply.
Quote from: Liartes on 19:52, 02 September 20I teared down the cpc 464 for a good clean and while removing the tape deck, these pieces fall. Do you have any clue where they come from ?Still waiting for the Z80 IC but regarding the general state after a good clean, I have very little hope to see it working again.
Quote from: gerald on 21:17, 02 September 20There is also a small spring.
Quote from: gerald on 18:43, 28 August 20Except that the WEKA doc is wrong : 40007 and 40008 are footprint compatible. I've never seen a 664 with anything else than a 40010 while they say that the 40008 was introduced with the 664.See also that 464 with a 40008 and note on which socket it is mounted : https://www.cpcwiki.eu/index.php/File:CPC464_PCB_Top_(Z70200_MC0002D)_GA40008.jpg
Quote from: dragon on 21:39, 11 September 20I think, they refer in the sense of" we introduce it in the time when 664 was released". In the 464 board manufactured at time when 664 was released.
Quote from: dragon on 21:39, 11 September 20Litte offtopic at finish you have documented the changes between 40007/8/10a/10b?
Quote from: gerald on 10:24, 12 September 20Well, they clearly introduce the 40008 as an improved version of the 40007 made for the 664. "La version 40008, utilisée sur le CPC-664 est la version améliorée du 40007 (pour le CPC-464)"I did not do the reverse engineering of the 40007/40008, but the die pictures are strictly identical from a mask point of view. So either the decaped 40008 was a re-marked 40007, or the 40008 is only an process evolution of the 40007.40010 version are, from a quick check, only a re-implementation of the same logic on a smaller (and therefore cheaper) gate array.
Quote from: dragon on 12:11, 12 September 20No, remarked not. At simply view they change things. They produce less heat. And at least the draw are different in some zones but same in others.
Quote from: gerald on 13:04, 12 September 20Attached is a picture of the 40007/40008 die photo differences. These are mainly : - scratches on the die - dirt remaining from decapping (mainly on the 40007) - slight offset due to stitching errors. The metal layer is clearly identical on both die, and this is the only thing that customer can customise in a GA. The only explanation for a lower consumtion is a change in the manufacturing process.
Quote from: gerald on 22:25, 14 September 20Interestingly, the 40007 is referred as a 20RA023 (2000 gates), while the die picture of both 40007/40008 are 16RA032 (1600 gates). It mean, at least, that amstrad moved to a smaller array. But was it during the 40007 development, during 40007 shelf life (like 40010 AA36/AA37) or as 40008 ?@robcfg : did anyone took a picture of the package before decapping ?
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