Topics

1802 vs 1805/6


Richard
 

Hello Magnus!

Most of the 1800 series are a bit dated unless you want to build a computer completely 'retro'.

Among those you mentioned there also is the CDP1851. This one is a dual parallel IO port. Both ports can be configured for input, output, bidirectional and bit mode. I have seen that similar devices have been used to build IDE interfaces or to read input from a PS/2 keyboard or mouse. This one may be quite interesting.


Lee Hart
 

On 6/26/2010 2:14 AM, Magnus wrote:
Yo!

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.
The 1804/5/6 are slightly improved versions of the 1802. Depending on the particular model, they have internal ROM, RAM, a timer, and some new instructions. They were intended for single-chip microcontroller applications, where you ordered them with your program already in the internal ROM.

Not much code was written to use the new instructions. The internal ROM is useless for general purpose applications; it is typically disabled so you can use it with external memory chips instead.

The only thing missing in the 1804/5/6 that the 1802 has is the LOAD mode. Unfortunately, LOAD is used in the Elf computers for their front panel interface.

I bought some 1805's on eBay for a good price. If you'd like to experiment, I'd be happy to swap one for an 1802.
--
Lee A. Hart | Ring the bells that still can ring
814 8th Ave N | Forget the perfect offering
Sartell MN 56377 | There is a crack in everything
leeahart earthlink.net | That's how the light gets in -- Leonard Cohen


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:

Magnus,

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
Overview.)


--
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)


Yo!

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.

/Magnus



------------------------------------

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



granz_consult
 

Magnus,

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
Overview.)


--
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)


Yo!

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.

/Magnus


Magnus Kesselmark
 

Hello Bob!

Thanks a lot for your answers. However there were so much more nice stuff in the list:
CDP1851, 1852, 1853, 1856, 1857, 1858, 1859, 1861, 1867, 1868, 1870, 1871, 1872, 1877, 1879 and some more ...

Magnus

----- Original Message -----
From: Bob Armstrong
To: cosmacelf@...
Sent: Saturday, June 26, 2010 4:31 PM
Subject: RE: [cosmacelf] 1802 vs 1805/6



Magnus,

>My question is, is there any idea to grab an 1805/06 instead of the 1802
"just in case

Two things -

* The 1805/6 doesn't have LOAD mode, so if you plan to use a traditional
Popular Electronics Elf style lights and switches "front panel" then you
must have the 1802.

* The 1805/6 does have some nice extra instructions, but AFAIK there's no
software floating around out there for the 180x that uses them. So unless
you're planning to write a lot of your own software, the extra opcodes are
pointless.

Bob Armstrong


 

Magnus,

My question is, is there any idea to grab an 1805/06 instead of the 1802
"just in case

Two things -

* The 1805/6 doesn't have LOAD mode, so if you plan to use a traditional
Popular Electronics Elf style lights and switches "front panel" then you
must have the 1802.

* The 1805/6 does have some nice extra instructions, but AFAIK there's no
software floating around out there for the 180x that uses them. So unless
you're planning to write a lot of your own software, the extra opcodes are
pointless.

Bob Armstrong


Magnus Kesselmark
 

Yo!

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.

/Magnus