On Sun, Jan 10, 2016 at 03:57:23PM -0600, Jim Brain wrote: >I have long been intrigued by the Tandy Color Computer Multi-Pak >Interface (MPI), and I'd like to try my hand at creating a similar idea >for the VIC-20. For the record, there already exists a dumb version of this: the Vic-1020 expansion chassis ("docking station"). http://sleepingelephant.com/denial/wiki/images/9/9e/Vic1020.gif Looking at the schematic diagram, it is pretty simple: two 74LS244 and one 74LS245 for buffering the address and data lines, and some logic to drive the direction of the 74LS245 data bus buffer. >It seems like it would be beneficial to have some control over the >cartridge slot, to turn things on/off, or maybe even remap things. I >was thinking of a design where: > >* 3 switches on the unit would control initial state (on/off) >* Users could remap BLK1,2,3,5 to another blk per slot (BLK1 in SLOT 1 >would actually trigger BLK2, allowing 2 8k RAM expansion to make a >16kB RAM >* Users could unmap portions of IO2 or IO3 per slot (effectively fully >decoding IO2 so multiple carts at IO2 base could share the space). > >Yes, probably of limited utility, but I thought it would be interesting >to see whether it could be done. Isn't this whole hobby of limited utility? How many cartridges are there that use I/O2 or I/O3 for something? That is a genuine question; I would like to see a list. A pragmatic answer could be that a single flash+RAM cartridge would cover most needs. The main question seems to be how to use such a mega-cartridge together with I/O expansion cartridges. A purist answer is that of course you would want some way to plug in multiple original ROM cartridges at a time and select which one to play. Marko Message was sent through the cbm-hackers mailing listReceived on 2016-01-11 08:00:09
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