From: Nicolas Welte; address is valid for replies (Re:) only! (welte_spam_at_freenet.de)
Date: 2003-01-23 11:32:58
Marko Mäkelä wrote:
>>just curious.... will that cart include full mem-expansion (ie 27k) and if
>>so, will it be useable with any other "normal" program?
>
>
> Yes, but the expansion blocks at $400-$fff and $2000-$3fff are mutually
> exclusive and use the same block of memory on the 62256. In BLK5, you
> can select RAM or one of the 512 banks of Flash ROM. BLK2 and BLK3 are
> always active. For maximum compatibility, the control registers at $9800
> and $9801 can be switched off by setting the most significant bit of $9801.
Maybe my expansion is better suited to be used as a 27kB expansion, but it
can only be installed inside a VIC-20CR because of space issues inside the
original VIC-20: http://people.freenet.de/x1541. After all, I never planned
it as an expansion for the VIC-20, but it needed only some small changes to
the GAL equations.
It offers a full 32kB from $0000-$7fff ($0-$1fff video RAM is write through
to onboard memory) without restrictions, four banks cartridge ROM at BLK5 and
four banks of BASIC/KERNAL ROM, both are in-system-programmable. There are no
registers to select the banks through software, this is done with DIP switches.
I could configure the device to show RAM at BLK5, but this would be the same
RAM that is at $2000, so it is not useful at all.
> BTW, you can get 5 samples of the MAX232CSE clone DS14C232CM from Dallas
> (or was it National Semiconductors). I got 5 chips in that way, to get
> something like a total of 110 or 111 chips for the production run of the
> C2N232, since the local distributor only sold complete tubes of chips.
I never got the samples I requested, so I bought them at Reichelt. Dallas was
nice to me two years before, when they sent me two smart clock samples that
plug into the ROM socket of many devices. CMD supports it in the FD2000 and
that's where I plugged one of them.
BTW Marko, I will buy one of your expansions of course.
Nicolas
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