Re: 1802 vs 1805/6

Ray Sills <raysills@...>

Hi Art:

Hmmm. That suggests that you could put an 1805 or 1806 into a VIP. The VIP has an "OS" in ROM, which is invoked when you hold down the hexpad key "C" when switching to RUN mode. Now the question becomes, would those extra instructions really be useful on the VIP platform?

73 de Ray

On Jun 26, 2010, at 12:37 PM, Art G. Granzeier III wrote:


Nice find.

The answer to your question is: (as usual) it depends. The 1805/6, as you
mentioned, has more instructions and is a bit more powerful. However,
what it is lacking is the Program Load mode built in to the processor. If
you are running a system with a ROM startup routine, then the 1805 will
work fine (it is fully object code compatible with the 1802), but if you
are running a Classic Elf-class system with no ROM and the toggle switches
to load your programs, then the 1805 will not work. This is mentioned in
Spare Time Gizmo's Elf 2000 manual (pg. 2, the last bullet point under the

Art G. Granzeier III
President, Granzeier Consulting
Helping to build a better engineer.

1802 vs 1805/6
Posted by: "Magnus" tubes@... soundbrigade
Sat Jun 26, 2010 12:14 am (PDT)


I was looking for cheap (surplus) components at small components shop
here >in Sweden when I spotted lots of COSMAC chips in the list. OF
COURSE there >was the 1802, which I just bought on eBay ...but also
1805/6. The latter >has some extra functions like internal
timers/counters and extra >instruxctions.
My question is, is there any idea to grab an 1805/06 instead of the 1802
"just in case ..." or will the original 1802 do most (all) work
brilliant >w/o the extra frills and laces?

I'd be hoping to grab some latches/decoders and buffers as well as IC
sockets for wiring, something I cannot find just like that here in
Sweden >any longer.



Visit the COSMAC ELF website at http://www.cosmacelf.comYahoo! Groups Links

Join to automatically receive all group messages.