[Coco] 2764 EPROM

[Darren A.]

>From: "Bruce W. Calkins"
>Subject: Re: [Coco] 2764 EPROM
>Date: Fri, 7 Sep 2007 19:03:06 -0400
>
>Yes, the Radio Shack/Tandy  FD-502 takes a 2764, or with a hack, the 27128.
>

The FD-502 can actually accept a 2764, 27128, 27256 or 27512, so long as you 
program your code into the highest 8K address space of the device. This is 
because Tandy tied the A13, A14 and A15 address lines to +5V. If you want to 
use 16K of the EPROM, then you need to disconnect the A13 pin from +5V and 
connect it to the A13 pad on the card edge.

I often use an SST 27SF512 Flash EEPROM in my FD-502 to test modifications 
to Disk Basic. It beats having to use a UV eraser.

Darren

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