CDP 1861 Replacement Circuit Questions
- I printed out Mr. Hart's 1861 replacement schematic that is in the files section.
C:ORCAD\SHEET\1802\1861.SCH Rev A 02172003
Was making a list of the integrated circuit used in the circuit so I could place an order for parts. That's when I was surprised to notice that the circuit uses an EPROM. What data should be burned on to the EPROM?
I looked at the old messages and could not find the answer. Perhaps I missed it.
Also, were there later revisions of this circuit created? Were PCB graphics ever made available?
- Dave Jones did a review of the TL866CS on his EEVBLOG.- Tom
--- In firstname.lastname@example.org, "joshbensadon" <joshbensadon@...> wrote:
> --- In email@example.com, "thinkpast" hjohnson@ wrote:
> > http://www.retrotechnology.com/herbs_stuff/gal.html
> > Some of the simplest PROMS can just be poked at and manually programmed. I reference some of that work on another Web page linked to the above page.
> > Herb
> Thanks Herb,
> Your web site lead me back to do another search on Ebay. I searched a few years ago without success, but now there are several to choose from!
> -TL866CS -$49
> -TOP853 $46 (does not list GAL 22V10)
> -TOP3000 $160
> -G540 -$60
> -G840 -$80
> -RT809F -$88 (does not have large ZIF socket, less versatile?)
> Several of these models include RAM testing and other CMOS Chip Testing, very impressive (if the tests are rigorous?).
> For these prices, it's not worth messing about building a home brew programmer. Heck, I've paid more for an adapter on my Andromeda Labs programmer.
> Right now I'm considering the G840, just on a hunch, but if anyone here can offer any advise, it would be much appreciated.