8086 uP Require

[Ralph Wade Phillips]

Howdy!

The way I heard the story, IBM used the 8088 because they had an 8088 ICE
blue box.

Nope.

They were already using the 8086 (IBM DisplayWriter) and the 8088,
being an 8 bit micro, used cheaper I/O chips and could be stuffed with 9
DIPs for a byte (8 plus parity).

RwP

 

[Phil Hobbs]

I knew if i kept that original '84 IBM PC it might be useful to someone or
worth something again one day now if i could get the original price for i
would be very happy

Nah, the PC came out in '81. My dad had the first one in town, with two
160k (not 360k) 5-1/4 inch floppy drives, a monochrome monitor, no
graphics, and a modified Selectric typewriter with a serial port.

Magic.

Cheers,

Phil Hobbs

 

[:-)]

I have two Fujitsu 8086-2 (date code 8728) and one 8088-2 (date code 8719).

So where would you like me to post one 8086?

And what's it worth? :->


If anyone is interested in homebrew Z80 systems I have about ten each of Z80
CPU, CTC, SIO-0 and eighty 4164 chips.

Do you have also a 8087-2 ?
;-)
It could be very fun to run thoses old FFT programs at full speed on my
old XT

 

[Peter A Forbes]

Nah, the PC came out in '81. My dad had the first one in town, with two
160k (not 360k) 5-1/4 inch floppy drives, a monochrome monitor, no
graphics, and a modified Selectric typewriter with a serial port.

Magic.

Cheers,

Phil Hobbs

We have a selection of oldish machines around here, Osbornes (2) Philips P2000C
(3) IBM PS/2 Model 30 and 50, couple of each. Don't use them anymore although
the Philips occasionally get run up as they have old data on them. I think most
were CP/M OS except the IBM's which were early MD-DOS. The Philips have a
converter/RAM card that runs MS-DOS 2.01 or thereabouts and usefully can write
both CP/M and MS-DOS floppies. That has an 8088 I think.

Peter

 

[Pooh Bear]

Amstrad that was the cheaper knock off (competition) for IBM PC ?

Yes but it wasn't a knock off. They actually made some decent LSI chips that
integrated much of the motherboard fumctions.
The first example of such design I ever saw in fact. Wasn't the PC's glue logic
made of lots of 74 series ?


Graham

 

[Tim Williams]

Do you have also a 8087-2 ?
;-)
It could be very fun to run thoses old FFT programs at full speed on my
old XT

I popped an 8087 into my Amstrad (PC1614DD I think?), sent that thing FLYIN!
;-)

Tim

 

[Peter A Forbes]

Yes but it wasn't a knock off. They actually made some decent LSI chips that
integrated much of the motherboard fumctions.
The first example of such design I ever saw in fact. Wasn't the PC's glue logic
made of lots of 74 series ?

Graham

We used to deal with a surplus electronics dealer in Loughborough, UK, who had a
large rack of all the special Amstrad IC's which he couldn't shift. There were
thousands of them, all basically scrap. Lost the lot in a fire a few years back.

Peter

 

[Tam/WB2TT]

Howdy!



Nope.

They were already using the 8086 (IBM DisplayWriter)

That's not to say the group doing the PC had one

and the 8088,
being an 8 bit micro, used cheaper I/O chips

The 8088 and 8086 used the same IO chips.

and could be stuffed with 9
DIPs for a byte (8 plus parity).

I don't know how many would have gone out the door like that. 9 DIPs was
16K.

Tam

 

[Michael A. Terrell]

That's not to say the group doing the PC had one


The 8088 and 8086 used the same IO chips.


I don't know how many would have gone out the door like that. 9 DIPs was
16K.

Tam

Have you ever seen an original IBM PC motherboard? It had a cassette
port, the floppy controller and drive(s) were optional. There were four
rows of nine sockets for the 16K * 1 RAM chips, and the firmware was in
multiple 8 bit EPROMs, including their version of BASIC. The board only
supported 64 K of RAM as shipped, and you only had a couple open slots
to stuff with RAM boards that held up to 256K per board. If I can find
it, I will scan the topside of the motherboard and post it to ABSE in a
couple days.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[Michael A. Terrell]

Nah, the PC came out in '81. My dad had the first one in town, with two
160k (not 360k) 5-1/4 inch floppy drives, a monochrome monitor, no
graphics, and a modified Selectric typewriter with a serial port.

Magic.

Cheers,

Phil Hobbs

I ran into a retired EE from IBM who had worked on the PC project a
few years before he retired. He had one of the first batch made for in
house use, and they let him take it when he retired. There were slight
differences from the production version, but you had to put it beside a
production version to spot them. He was in tears when I returned it to
him after I replaced a failed floppy controller card that had failed. A
local computer store had not only refused to look at it, but the owner
was screaming at him to toss it in his dumpster and buy a new computer
when I ran into him in the computer store. He was shouting, No one in
the world has a floppy controller card for that piece of junk! I
laughed and told the old man that I had a couple dozen good spares in my
collection and he was welcome to one.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[Rob B]

Nah, the PC came out in '81. My dad had the first one in town, with two
160k (not 360k) 5-1/4 inch floppy drives, a monochrome monitor, no
graphics, and a modified Selectric typewriter with a serial port.

yea you are on, my memory isn't so great anymore, it was probably an '82
vintage as it had the 2 x 5 1/4 ?360K? floppies with CGA color display card
and a memory expansion board. the manual mentions the ?hercules? monocrome
card. the engineering firm my dad worked for purchased several as group for
a discount and were using them to run some CAD application BasicCAD,
CADBasic or something CAD seems i remember it was PIA to use

 

[Tam/WB2TT]

Have you ever seen an original IBM PC motherboard? It had a cassette
port, the floppy controller and drive(s) were optional. There were four
rows of nine sockets for the 16K * 1 RAM chips, and the firmware was in
multiple 8 bit EPROMs, including their version of BASIC. The board only
supported 64 K of RAM as shipped, and you only had a couple open slots
to stuff with RAM boards that held up to 256K per board. If I can find
it, I will scan the topside of the motherboard and post it to ABSE in a
couple days.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

Never saw an actual IBM MB, but did have the original AT&T 8086 version.
Sounds like the same thing, except the AT&T went modern with a floppy drive,
and no tape. Did the IBM original use an MC6845 for driving the display?
Occurs to me, that probably cost more than the 8088.

Tam

 

[JeffM]

the manual mentions the ?hercules? monocrome card.

Rob B

Yup. HGC.
http://66.102.7.104/search?q=cache:...20-*-348+CGA-emulation-*+competing-technology

 

[Winfield Hill]

Michael A. Terrell wrote...

Have you ever seen an original IBM PC motherboard? It had a cassette
port, the floppy controller and drive(s) were optional. There were four
rows of nine sockets for the 16K * 1 RAM chips, and the firmware was in
multiple 8 bit EPROMs, including their version of BASIC. The board only
supported 64 K of RAM as shipped, and you only had a couple open slots
to stuff with RAM boards that held up to 256K per board. If I can find
it, I will scan the topside of the motherboard and post it to ABSE in a
couple days.

Yep, and the 8088. We got our first one about 1 year after they
started production, and the thing that amazed me was the mobo had
a half-dozen jumper-wire modifications.

I'm pretty sure the reason they used the 8088 instead of 8086 chip
was to keep what later became known as the ISA bus, more simple.

 

[Michael A. Terrell]

Never saw an actual IBM MB, but did have the original AT&T 8086 version.
Sounds like the same thing, except the AT&T went modern with a floppy drive,
and no tape. Did the IBM original use an MC6845 for driving the display?
Occurs to me, that probably cost more than the 8088.

The 8088 wasn't a cheap part when the original PC was designed. It,
and the other Intel chips probably cost more than the rest of the chips
on the motherboard. The 16K * 1 memory chips were quite common at the
time, and I think that the non floppy version was shipped with only 32K
of RAM. If I can find it, I had the BYTE magazine with the original
press release for the PC, and another with their review of the first PC.

BTW, did you know that you could convert the 256K XT motherboard to
the 640K version by plugging a chip into an empty socket, and soldering
two adjacent pads together? Then you replaced the first two banks of
RAM with 256K chips to get 640K. When I was still repairing the
original XTs I did that modification to a lot of them to free up several
expansion slots, and to reduce the load on the small power supplies.
The non hard drive versions were shipped with a 63 watt supply.

As far as the 6845, I did see them in the early PCs and clone video
boards.

--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[Tam/WB2TT]

The 8088 wasn't a cheap part when the original PC was designed. It,
and the other Intel chips probably cost more than the rest of the chips
on the motherboard. The 16K * 1 memory chips were quite common at the
time, and I think that the non floppy version was shipped with only 32K
of RAM. If I can find it, I had the BYTE magazine with the original
press release for the PC, and another with their review of the first PC.

BTW, did you know that you could convert the 256K XT motherboard to
the 640K version by plugging a chip into an empty socket, and soldering
two adjacent pads together?

I did a 68000 design in the same time frame (while sneering at Intel). Used
64K DRAMs, but the first batch cost us about $100 each. That's why I was
pretty sure they were not used in the first PC. Got the thing to legally run
at 12 MHz with 0 wait states from the 128K onboard DRAM. Running C
benchmarks showed performance about equal to a VAX. I may still have the
same Byte magazine you allude to.

Tam

 

[[email protected]]

I've got an 8086-2 here, it was also out of an old Amstrad. I don't
know if it still works but its possible.


If you want it, go to www.cwgsy.net/private/mandoline and send email to
that address.

-A

 

[Mike Berger]

Maybe if it were new in the original sealed box. I saw an IBM AT
sealed box go for $ 50 at an auction just a couple of years ago.
I doubt the original IBM PC carries a lot of collectible value.
There are still thousands in garages and basements.

 

[Keith Williams]

The 8088 wasn't a cheap part when the original PC was designed. It,
and the other Intel chips probably cost more than the rest of the chips
on the motherboard. The 16K * 1 memory chips were quite common at the
time, and I think that the non floppy version was shipped with only 32K
of RAM. If I can find it, I had the BYTE magazine with the original
press release for the PC, and another with their review of the first PC.

The first IBM PC (5150) floppy only system shipped with 16k
minimum. IIRC the floppy version shipped with 48K minimum. The
max on-board was 64K. IIRC 16K memory chips weren't all that cheap
at the time, particularly 36 of 'em.

BTW, did you know that you could convert the 256K XT motherboard to
the 640K version by plugging a chip into an empty socket, and soldering
two adjacent pads together? Then you replaced the first two banks of
RAM with 256K chips to get 640K. When I was still repairing the
original XTs I did that modification to a lot of them to free up several
expansion slots, and to reduce the load on the small power supplies.
The non hard drive versions were shipped with a 63 watt supply.

Yep. I upgraded hundreds of 'em. I had acess to "free" 64K chips
(came off life test. However the 256K (so called) PC-2
motherboard couldn't be upgraded easily. The XT designers added
the upgrade "under the table".

As far as the 6845, I did see them in the early PCs and clone video
boards.

I'd have to look at mine. I don't remember what it has in it.

 

[Kryten]

Do you have also a 8087-2 ?

Alas, no.

I'll look out for one.

I've packed up an 8086-2 for Wayne L, that will start its journey to him
tomorrow.