FS: 32k or 35k RAM expansion

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eslapion
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FS: 32k or 35k RAM expansion

Post by eslapion »

There always seems to be a shortage of low cost 32k or 35k RAM expansions to be able to play newer games on the VIC-20.

I have a few spare 32k x 8 and 8k x 8 SRAM chips and a dead Avenger cartridge so I thought I could make a good memory expansion out of this.

I can make it 32k or 35k. One switch for RAM/ROM mode and perhaps another to enable/disable the 3k section.

Any taker ? price offer ? capacity desired ?
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Re: FS: 32k or 35k RAM expansion

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PM sent.
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eslapion
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Re: FS: 32k or 35k RAM expansion

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Muzz73 wrote:PM sent.
Replied!
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Kakemoms
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Re: FS: 32k or 35k RAM expansion

Post by Kakemoms »

eslapion wrote:There always seems to be a shortage of low cost 32k or 35k RAM expansions to be able to play newer games on the VIC-20.
What would you consider a low price for a 35k expansion?
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eslapion
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Re: FS: 32k or 35k RAM expansion

Post by eslapion »

Kakemoms wrote:What would you consider a low price for a 35k expansion?
35$US or 31.50 Euros, with RW/RO and 3k switches and a reset pushbutton.

How does that sound ?
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Re: FS: 32k or 35k RAM expansion

Post by Kakemoms »

eslapion wrote: 35$US or 31.50 Euros, with RW/RO and 3k switches and a reset pushbutton.

How does that sound ?
Maybe add IO2/3 for 37KB? If you put in a larger SRAM and a flip-flop you could make it paged.
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Re: FS: 32k or 35k RAM expansion

Post by eslapion »

Kakemoms wrote:Maybe add IO2/3 for 37KB? If you put in a larger SRAM and a flip-flop you could make it paged.
Yuk! This is a SRAM chip placed on a VIC-20 game cart and the HCT08 chip needed to re-encode the BLK lines into 2 address lines is literally hanging in place by the Vcc and GND pins. If I make it 35k, I have to piggyback another 8k x 8 chip on top of the 32k x 8 and 3 diodes on the RAM lines for the 3k expansion !CS.

Since the IO2/3 areas are in the top part of a BLK and the 3k RAM expansion are in the bottom, you could just add 2 more diodes to the !CS to get 37k and let the 8k x 8 chip use the address lines for proper memory chip usage.

Adding a flip-flop for paging to such a dense setup is just plain unthinkable.
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