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Is that not the distinction between Chip RAM and Fast RAM in real machines? https://en.wikipedia.org/wiki/Amiga_Chip_RAM https://en.wikipedia.org/wiki/Amiga_Ch

Is that not the distinction between Chip RAM and Fast RAM in real machines? https://en.wikipedia.org/wiki/Amiga_Chip_RAM https://en.wikipedia.org/wiki/Amiga_Chip_RAM

rasz 1y ago
Afaik only A3000 and A4000 shipped with Fast ram, both computers werent really price competitive with PCs.
actionfromafar 1y ago
A large amount of Fast Ram would have been even more useful, but if you are cost optimizing the BOM, just a tiny sliver of it (it being Fast RAM) would have been effectively a "manual cache" managed by the developer and would have been incredibly useful for anything computation intense, like flight simulators, spreadsheets, anything not involving just blitting graphics really.
- rasz 1y ago
  And it wouldnt even be that hard, just two 2kx8 SRAMs (like the ones in every NES/Famicon) and CS line going from the chipset to map it somewhere high outside the range of the chipset was very logical, easily doable in 1987 and most importantly cheap. Those 6116 srams were below $2 retail in 1987 (Byte magazine retail prices), so $4 for big performance boost. Hell, smart Commodore would design A500 with second trapdoor near the CPU. Ship unpopulated but offer official Commodore "turbo ram" expansion carts: - $25 4KB version. $8 BOM, 2x $1.95 6116 - $40 8KB. $12 BOM, 2x $3.5 6264 - $100 64KB. $28 BOM, 2x $12 62256 - Extreme $400 256KB. $120 BOM, 8x $12 62256. Would stick out due to big PCB so make it an attractive piece of plastic with cool logo and "EXTREME" design. Map it at D80000 (potential 256KB of space for activities) and let software vendors auto detect fitted option by running quick memory test. Easy speed boost and easy extra money for Commodore.
  - lproven 1y ago
    I tried to answer at greater length here: https://news.ycombinator.com/item?id=45745754 https://news.ycombinator.com/item?id=45745754 But I think in reality, less money for Commodore because of sales lost to the now-even-cheaper Atari ST.
- lproven 1y ago
  I think I see where you are coming from now. You are not saying "there was no uncontended RAM in the Amiga", which is what I understood you to mean. You are saying "the Amiga did have uncontended RAM but it did not ship with any as stock." Is that right? If so, yes, true, but the key things here IMHO are: 1. The Amiga was designed and built as a games console, one which happened to be able to do other things. It was primarily marketed and sold as a games machine. I wrote about an Amiga-compatible OS recently: https://www.theregister.com/2025/05/22/aros_live/ https://www.theregister.com/2025/05/22/aros_live/ And the comments are from slightly baffled readers asking if this is any good for running their old Amiga games, or how this makes gaming any easier. (It is not and it does not, but that is what people perceive the Amiga as being for in the 21st century.) 2. In the real 1980s market, the Amiga's glory was to a large extent stolen by the Atari ST. The ST was a much more limited machine but it was vastly better than any 8-bit machine, and an entry-level ST was more usable than an entry-level Amiga. ST games were pretty good for the mid-1980s when a lot of people still had ZX Spectrum or Commodore 64 level kit. Many games companies targeted the lower-end machine and ported to the higher-end one. The Amiga was competing with the cheaper, simpler ST in the market, and keeping the costs down became imperative. That's why Commodore didn't add more hardware or more RAM to the base-level Amiga. In fact for the Amiga 600 took the spec of the A500 and cut it down. I am not arguing that some Fast RAM as stock wouldn't have been good. It would. But probably irrelevant to most gamers, and probably would have hurt the machine's sales.
  - actionfromafar 1y ago
    I am convinced as little as 32 bytes of uncontested (fast-ram) would have made wonders. It would almost have been like doubling the number of data registers on the 68000. Either an extra chip with address decoder and this scratch memory could have been placed on the 68000 memory bus... this would 100% have worked. Or much better, the Agnus chip could have had this scratchpad added into it. It should have been feasible - it had about 20k transistors IIRC and a few hundred more should have been doable. I am fairly certain this would have worked but I'm not completely sure, it depends on if that addition would have complicated multiplexing and/or internal bandwidth demands, but the 68000 ran at 7MHz at the time, so it doesn't seem too difficult to me, armchair designer. Thanks for the article! It's always nice to see AROS and Amiga get some love. :) Achschully AROS m68k can be helpful for playing your old Amiga games in an otherwise open source way. You don't have to buy or pirate the official Kickstar ROM images if you use an AROS m68k ROM instead. But on the other hand, realistically you would probably pirate that old Amiga game to begin with, it's not like you have your old floppies lying around and if you did, you'd need a floppy drive to read them anyways... Dieshot of Agnus: https://upload.wikimedia.org/wikipedia/commons/9/9f/CBM_8370R3_top_metal.jpg https://upload.wikimedia.org/wikipedia/commons/9/9f/CBM_8370...

Is that not the distinction between Chip RAM and Fast RAM in real machines? https://en.wikipedia.org/wiki/Amiga_Chip_RAM https://en.wikipedia.org/wiki/Amiga_Chip_RAM

rasz 1y ago

Afaik only A3000 and A4000 shipped with Fast ram, both computers werent really price competitive with PCs.

actionfromafar 1y ago

A large amount of Fast Ram would have been even more useful, but if you are cost optimizing the BOM, just a tiny sliver of it (it being Fast RAM) would have been effectively a "manual cache" managed by the developer and would have been incredibly useful for anything computation intense, like flight simulators, spreadsheets, anything not involving just blitting graphics really.

rasz 1y ago
And it wouldnt even be that hard, just two 2kx8 SRAMs (like the ones in every NES/Famicon) and CS line going from the chipset to map it somewhere high outside the range of the chipset was very logical, easily doable in 1987 and most importantly cheap. Those 6116 srams were below $2 retail in 1987 (Byte magazine retail prices), so $4 for big performance boost. Hell, smart Commodore would design A500 with second trapdoor near the CPU. Ship unpopulated but offer official Commodore "turbo ram" expansion carts: - $25 4KB version. $8 BOM, 2x $1.95 6116 - $40 8KB. $12 BOM, 2x $3.5 6264 - $100 64KB. $28 BOM, 2x $12 62256 - Extreme $400 256KB. $120 BOM, 8x $12 62256. Would stick out due to big PCB so make it an attractive piece of plastic with cool logo and "EXTREME" design. Map it at D80000 (potential 256KB of space for activities) and let software vendors auto detect fitted option by running quick memory test. Easy speed boost and easy extra money for Commodore.
- lproven 1y ago
  I tried to answer at greater length here: https://news.ycombinator.com/item?id=45745754 https://news.ycombinator.com/item?id=45745754 But I think in reality, less money for Commodore because of sales lost to the now-even-cheaper Atari ST.
lproven 1y ago
I think I see where you are coming from now. You are not saying "there was no uncontended RAM in the Amiga", which is what I understood you to mean. You are saying "the Amiga did have uncontended RAM but it did not ship with any as stock." Is that right? If so, yes, true, but the key things here IMHO are: 1. The Amiga was designed and built as a games console, one which happened to be able to do other things. It was primarily marketed and sold as a games machine. I wrote about an Amiga-compatible OS recently: https://www.theregister.com/2025/05/22/aros_live/ https://www.theregister.com/2025/05/22/aros_live/ And the comments are from slightly baffled readers asking if this is any good for running their old Amiga games, or how this makes gaming any easier. (It is not and it does not, but that is what people perceive the Amiga as being for in the 21st century.) 2. In the real 1980s market, the Amiga's glory was to a large extent stolen by the Atari ST. The ST was a much more limited machine but it was vastly better than any 8-bit machine, and an entry-level ST was more usable than an entry-level Amiga. ST games were pretty good for the mid-1980s when a lot of people still had ZX Spectrum or Commodore 64 level kit. Many games companies targeted the lower-end machine and ported to the higher-end one. The Amiga was competing with the cheaper, simpler ST in the market, and keeping the costs down became imperative. That's why Commodore didn't add more hardware or more RAM to the base-level Amiga. In fact for the Amiga 600 took the spec of the A500 and cut it down. I am not arguing that some Fast RAM as stock wouldn't have been good. It would. But probably irrelevant to most gamers, and probably would have hurt the machine's sales.
- actionfromafar 1y ago
  I am convinced as little as 32 bytes of uncontested (fast-ram) would have made wonders. It would almost have been like doubling the number of data registers on the 68000. Either an extra chip with address decoder and this scratch memory could have been placed on the 68000 memory bus... this would 100% have worked. Or much better, the Agnus chip could have had this scratchpad added into it. It should have been feasible - it had about 20k transistors IIRC and a few hundred more should have been doable. I am fairly certain this would have worked but I'm not completely sure, it depends on if that addition would have complicated multiplexing and/or internal bandwidth demands, but the 68000 ran at 7MHz at the time, so it doesn't seem too difficult to me, armchair designer. Thanks for the article! It's always nice to see AROS and Amiga get some love. :) Achschully AROS m68k can be helpful for playing your old Amiga games in an otherwise open source way. You don't have to buy or pirate the official Kickstar ROM images if you use an AROS m68k ROM instead. But on the other hand, realistically you would probably pirate that old Amiga game to begin with, it's not like you have your old floppies lying around and if you did, you'd need a floppy drive to read them anyways... Dieshot of Agnus: https://upload.wikimedia.org/wikipedia/commons/9/9f/CBM_8370R3_top_metal.jpg https://upload.wikimedia.org/wikipedia/commons/9/9f/CBM_8370...