[Coco] OTPROMs and MPUs

[Dave Philipsen]

If anyone is interested I have a bunch of brand new OTP (one-time 
programmable) 27C256s left over from when I used to buy them by the 
hundreds (28-pin DIP).  I believe most of them are Atmel but I'd have to 
check.  I have tubes and tubes of them.  You can have them for a buck 
apiece or maybe cheaper in quantity.  One time programmable though.  
They are plastic cases with no quartz window for erasing although Marty 
Goodman once said they could be erased with X-rays.  I've never had the 
luxury of verifying that.

I don't know if I've mentioned it here before or not but I also have at 
least a hundred MC68HC11F1CFN4 chips that could be had for around $6 
apiece.  The instruction set is very similar to a 6809 but a little more 
restrictive.  Pretty much the same basic internal registers.  This chip 
has the full non-multiplexed address and data bus that will run at an 
internal clock speed of 4 MHz.  It's got a bunch of extra MPU type stuff 
too like I/O ports, timers, watchdog, UART, SPI, etc.  If you're into 
hardware and are familiar with Motorola 8-bit stuff then this would be 
right up your alley.

Dave Philipsen


On 12/10/2015 7:51 PM, Al Hartman wrote:
> I've been buying old Carts on eBay for $5.99 - $6.99 including shipping.
>
> Mark's Coco Cartridge boards are about $6 and change (you have to 
> order 3 at a time from OSHPark), though you could get them cheaper by 
> going overseas and ordering a lot of them.
>
> The parts are $2 - $3 depending on the EPROM you choose, and how much 
> you pay for them. (I bought a bunch of 27128's for less than $2.00 
> each, and some 2732's for under $1.00 each.)
>
> So, one could put together carts under $15.00 - $16.00 though 
> admittedly, the supply of cheap used Coco carts is unpredictable.
>
> -[ Al ]-
>