Mike,Mike wrote:"+32K" is commonly referred to as the RAM configuration with RAM in BLK1..3 and BLK5.Bit Shifter wrote:You need a VIC (or an emulator setting) with 40K !
32K is not enough, there must also be RAM in the block 5 ($A000-$BFFF).
If you also use the 3K in the address range $0400..$0FFF (like Kweepa did with VIC Doom or I did here), you'll often have to stress this out though: many people otherwise just ignore this or don't take this serious (like in: "but doesn't just +32K suffice?") and then wonder the program/tool/game doesn't run with "just +32K".
Those "+35K" (or "+32K +3K") are also the biggest common denominator, as this is the maximum RAM you can get on the VIC-20, if you:
- remain at an unbanked RAM setup (there is no agreed upon or at least wide-spread enough standard for banked RAM!), and
- leave the I/O area for its intended purpose, i.e. as I/O registers or other resource, strictly for the use by the cartridge firmware only!
+32K +3K is supported by Mega-Cart, FE3 and Ultimem. In case of FE3 though, due to issues with the CPLD firmware (*not* the FE3 menu firmware!), crosstalk between RAMx and BLKx can happen - mainly on NTSC VIC-20s, but this has also been reported on some PAL VIC-20s - rendering the +32K +3K configuration problematic for FE3 users.
thanks for the clarification.
My interpreter needs the +35K configuration, the one, you described above.
Even then it wasn't easy to put a highres bitmap, a font, the resident part of an Infocom story, a disk cache and the program itself into this amount of RAM. Normally Z interpreters run comfortably on machines with 48K RAM or more and then in text mode only.
The side effect is, that the disk cache is too tiny. Even simple commands like "inventory" or "look" access 10-20 different story pages (disk blocks of 256 bytes) and if the disk cache cannot store that many pages it loads them all for each command! Running the program on a real VIC-20 with a real 1541 can be painfully slow. I recommend an emulator with warp-mode or at least an accelerated disk access (JiffyDOS or others).
Bit Shifter