Post AlLsWsZZA5SwurKfD6 by bread80@mstdn.social
(DIR) More posts by bread80@mstdn.social
(DIR) Post #AlL86TK9ohjlBkax60 by bread80@mstdn.social
2024-08-25T21:38:45Z
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The second of my articles documenting creating a replacement Amstrad CPC gate array using a Raspberry Pi RP2350 microcontroller. This time I use a PIO, a DMA and an array of data to drive the six signals with fixed timings.Lots of nerdy detail for anyone wants to learn what a Pico is capable of, or for those who want a better understanding of the DMAs.https://bread80.com/2024/08/25/pico-garry-2350-part-2-fsigs-fixed-signals/#PicoGarry #PicoGarry2350 #Amstrad #AmstradCPC #RP2350 #Pico #Pico2
(DIR) Post #AlL86U27BGtnO5A3c0 by vik@mastodon.nzoss.nz
2024-08-25T22:51:12Z
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@bread80 The original CPC gate array simulator was called "The GAS Board," a play on the national natural gas vendor at the time. There was a small section we chopped out of it for ROM emulation, which started out being named as "The Small Gas Board" but inevitably ended up being referred to as "The Smörgåsbord."Guess who was on the dev team at Amstrad.
(DIR) Post #AlL86UogGhkNohsqJM by bread80@mstdn.social
2024-08-25T21:54:34Z
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BTW here's the scope trace of the signals being generated by the RP2350 at this stage.
(DIR) Post #AlLry0qqOEfESMmvyq by bread80@mstdn.social
2024-08-26T07:24:42Z
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@vik You we’re on the dev team? That’s really cool. Hardware or software?
(DIR) Post #AlLs9dQBKOk5GSrK1Q by vik@mastodon.nzoss.nz
2024-08-26T07:27:14Z
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@bread80 Mostly software but I have enough hardware knowledge to be dangerous, so they got me making a few diagnostic devices and I had a bit of input in the later PC hardware.
(DIR) Post #AlLsDMtaiCWVAZOZQu by vik@mastodon.nzoss.nz
2024-08-26T07:27:56Z
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@bread80 Dunno if you heard of Vax The Hairy Hacker, but that was me.
(DIR) Post #AlLsWsZZA5SwurKfD6 by bread80@mstdn.social
2024-08-26T07:31:24Z
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@vik Were you ever in ACU magazine? If so then yes, I remember.
(DIR) Post #AlLsZjVnJ2cRgPvePA by vik@mastodon.nzoss.nz
2024-08-26T07:31:57Z
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@bread80 Oh yes, that's the one. Glad someone does :)
(DIR) Post #AlLseHklwG9x2X6au0 by bread80@mstdn.social
2024-08-26T07:32:45Z
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@vik Is it true that each dev was assigned a different ‘pack’ in the firmware? If so which was yours?
(DIR) Post #AlLtDneXKTYs6r7htg by vik@mastodon.nzoss.nz
2024-08-26T07:38:30Z
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@bread80 Most of the really low-level stuff was done by MEJ Electronics, and the BASIC by Locomotive. Most of the Amstrad crew did ROMs, peripherals, diagnostics, testing, and system stuff for the CPC. After that we got a bit more involved, particularly with ANT, Spectrum, and PC firmware.
(DIR) Post #AlLwqRsGXEJjikfKzI by loke@functional.cafe
2024-08-26T08:19:44Z
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@vik @bread80 Now, "gas" in Swedish means precisely that, gas. "Gås" on the other hand means "goose".To provide even more information: "Smör" means "butter", and "bord" means "table".Do with this information what you wish.
(DIR) Post #AlLxKW0BkiD9D6hz7o by vik@mastodon.nzoss.nz
2024-08-26T08:25:13Z
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@loke"Goose butter" sounds like they're considering some form of paté.@bread80
(DIR) Post #AlLyzwZfxgUnRycreC by loke@functional.cafe
2024-08-26T08:43:45Z
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@vik @bread80 That is indeed a common dish on a Smörgåsbord.I'm also checking SAOB (an absolutely fascinating historical dictionary of the Swedish language, and I believe one of the most extensive ones in any language) on its entry for "gås": https://www.saob.se/artikel/?unik=G_1351-0227.e6fuAccording to this entry, one of the many ways in which the word was used was to refer to to cream when churned. I guess this is due to the way these pieces of butter would float on top of the cream like geese on water.This suggests that the word "smörgås" used to refer to pieces of butter, and it only later started to be used to refer to the entire sandwich (bread with butter on it). The dictionary points to examples of this usage of the word in a dictionary from 1538.
(DIR) Post #AlM6lvy2Dmw798qluq by nivrig@mastodon.social
2024-08-26T10:10:59Z
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@vik @bread80 Vax? Now there’s a name etc. ;)
(DIR) Post #AlMQ8jXeU2igOn5x2m by bread80@mstdn.social
2024-08-26T13:48:01Z
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@vik How much of the firmware and ROMs was specified by Amstrad and how much by the dev team doing what they thought was best? I’m always impressed at how the machine goes way above the minimums required for a games machine. Things like the interrupt system and firmware jumpblocks have the feel of a ‘grown up’ business computer.
(DIR) Post #AlMxyXC8vnGdeRLIvY by vik@mastodon.nzoss.nz
2024-08-26T20:07:10Z
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@bread80 Most of that stuff was done by MEJ, who were trying to fit the Amstrad spec into a teeny weeeny gate array as best they could. The dev team at Amstrad tested the bejesus out of it on the GAS boards through the interface supplied by Locomotive to make sure the thing was "punter proof."
(DIR) Post #AlMy0N9xDHFl6fCALI by vik@mastodon.nzoss.nz
2024-08-26T20:07:30Z
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@bread80 We passed our findings back, blowing revised EPROMs, and creating a damn fine user manual. There was a lot of reliability testing on things as mundane but important as the keyboard and cassette interface, and I joined in just after Amstrad started development of the disc drive.
(DIR) Post #AlQDVou8BqnQv37xHU by bread80@mstdn.social
2024-08-28T09:45:20Z
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@vik Yes, the documentation was excellent. I still have my original Soft168(?) firmware manual and I still use it regularly.
(DIR) Post #AlR55rU7MuyWuy1yca by vik@mastodon.nzoss.nz
2024-08-28T19:45:47Z
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@bread80I used the Amsoft one. For Spectrums we used The Spectrum ROM Disassembled because it was better than Sinclair's commented code.