I never understood why 256 kB wasn't supported by the real C128. Was it a hardware mistake?
Are you speaking about why the C128 didn't internally have 256 kb? And to be more specific, are you wondering why it was not originally created with 256 kb? Or are you asking why 256 kb was not built into it/added after the C128 originally came out?
Are you speaking about why the C128 didn't internally have 256 kb?
I'm wondering why you couldn't expand it from 128 to 192 or 256 kB after launch. It had the memory sockets and the MMU can be told to use bank 2 or 3 but for some reason (I forgot why) it's not possible without modifying the hardware.
I'm wondering why you couldn't expand it from 128 to 192 or 256 kB after launch.
According to Brian Bagnall's book, "Commodore: the Amiga Years", in 1986 CBM engineer Dave Haynie and others were left to try and figure a follow-up to the C128. (An aside... 128K seemed to be the magic number after 64K. Other than the C128, the other 128K computers were the Tandy Colur Computer 3 and the Atari 130XE.)
Dave wanted to have a C256 with a MMU that accessed all of the memory instead of bank-switching it. His C256 would have a 65816 chip, an internal disk drive, but no C64 compatibility. He wanted it to be a business computer.
His idea of a C256 was killed, because its pricing was too close to that of the B52 project (later renamed the Amiga 500).
Here and elsewhere, C128 fans have already grumbled over the lack of dual active video ports and lack of numeric keypad, and the fact it is not a drop in motherboard for any C128 case or configuration.
Then we mused over the TWENTY or so chips needed to be cannabilized from a real c128 in order to get this thing to work at a stunning 260 EUR... So OK .. the VICIIe/SIDs are not present and that part is OK, we get that SIDs (in particular) are hard to come by and emulation is meh meh..except for some recent stuff ... and then..8502/Z80/MMU/PLA/CIA not present.. fine, ok.. fine (SORT OF) .. but then, to top it all off .. 128RM project burdens us with ram and rom requirement. .. I can't escape the notion that the lack of RAM/ROM is a non-starter, at 260 EUR.
The ram replacement seems simple (!?).. 128RM project could just add a 1Mbit (or more) SRAM chip or whatever! The ROMset gets its due with just one flashram chip. Maybe Cloanto threatened 128RM with (c) stuff there, or is there simple paranoia going on over there v. (c) concerns ??
Meanwhile, assuming the project head was worried about (C) concerns with roms, in the first place. .. Underneath one rom socket, 128RM could have included one big fat flashram chip in there as a way for user to update roms on his/her own without having to physically deal with rom chips at all. (die eproms die)
Also.. does the 128RM project head NOT appreciate that some of these C128 chips are both BIG AND SOLDERED ? .. Maybe it's fine easy work removing those chips with the right tools but with normal tools those are 1) a pain to remove .. and .. 2) involve some risk of damage. Maybe it's fine to trash Z80A/B since those grow on trees it seems.. but 8502 isn't that super-commonly available, especially as a free floating part.
Also.. does the 128RM project head NOT appreciate that some of these C128 chips are both BIG AND SOLDERED ?
Hmm, this is a bit of a downer. I can accept that chips needs to be taken from original machine since machines break and getting a new machine out of broken ones will make the machine live longer. But desoldeing isn’t easy.
...this is a bit of a downer. I can accept that chips needs to be taken from original machine since machines break and getting a new machine out of broken ones will make the machine live longer.
I don't like the idea of scrounging up all those legacy chips (especially the hotter-running ones which may eventually fail). ...And the board at $294 US. I suppose it is supposed to be like the C64 Reloaded board, but I didn't like the idea of that one. Oh, well, the Ultimate 64 I ordered should be arriving in a few days.