Uncreative Labs

Joined: 07 Aug 2011 Posts: 24 Location: Las Vegas

I understand that the Tandy T1000 RL has a U4, Intel 8087 co processor installed as a standard option. This is the very same chip used for the IBM 5150 PC. Is the chip removable from the Tandy computer or is it soldered in place? Will the T1000 still function without it?

The reason I ask is that I haven't been able to locate one of these chips for sale and want to install one in my 5150 system as part of my 5150 build project. (Long story)

If I can't remove the chip from the Tandy, does anybody either have one for sale, or know where I can locate one? I do have a few ISA cards I'm willing to trade. If you're interested, please contact me.

Thanks for reading. Razz

Joined: 02 Oct 2004 Posts: 594 Location: Western NC

Quote:

...know where I can locate one?

Basically looks like the same store:

http://www.codemicro.com/store/product/Intel-d8087-Refurbished.php

http://www.partzdepot.com/store/product/Intel-d8087-Refurbished.php

Each shows only 1 in stock...

Irregardless, don't expect a big increase in performance, or expect to find much software that can utilize it. Only thing I had on mine that used it was Autocad 10.

Joined: 07 Aug 2011 Posts: 24 Location: Las Vegas

Cool, thanks. Where did you find the link? I searched Google, E-Bay and even Amazon.com and couldn't find one.

Joined: 02 Oct 2004 Posts: 594 Location: Western NC

Google Shopping

Joined: 07 Aug 2011 Posts: 24 Location: Las Vegas

Funny, I looked there too. I know Google does this stupid thing where people get different results from different locations, or even log on accounts. That is really a stupid idea.

Thanks again though. I just placed my order.

Joined: 02 Oct 2004 Posts: 594 Location: Western NC

Again, just don't expect much simply by adding a co-pro. There's little you can do (performance wise) for an XT-class machine, short of replacing the CPU itself with a NEC V20. I sank a lot of money (>$500) into my 5160, only to have it sitting in a dark corner of a basement.

Joined: 03 Feb 2006 Posts: 488 Location: pennsylvanai

an 8087 will help only those programs like lotus 123 that use a co processor
if not it just sits there
maximize the ram to 640 , faster ram does NOT lep
Optimize the hd interleave. use spitest.
the 3:1 fastese is really the slowest data transfrer
add the V20n cpu and find and run0- faxt bv20
choose a faster hard drive'like the better seagate st-241
the -1 is 28ms
but so are some st-251's are not 40ms but 28ms.
you must test. the seagate st225 are slower and the miniscribes are very slow.
sometimes there may be an advantag with a rll drive,
possibly because the interleave is 4:L1 but test to see what it fastest
this is done with a LOW LEVEL FORMAT
Yes you really can MUST do a LL format on a mfm drive.
since the IBM pc/xt is slower 4.77 ,hz, the interleave may even be 5:1 to be fastest.
it is REAL.

Joined: 07 Aug 2011 Posts: 24 Location: Las Vegas

I think a little explanation is in order.

As for software, I WILL be using Lotus 123 on the system for spreadsheet work and reporting. Yeah, it's not as rubust as Excel on a newer PC, but it will do what I need it for. Additionally, I'll be using other software for balancing checkbooks and other accounting functions, so yeah, the math co-processor will be a nice add-on.

Hardware wise; my system is an IBM 5150 with dual 360 Kb 5.25" DSDD floppy drives. There is no hard drive. It also has a full 640 Kb of RAM installed and a CGA graphics adapter, parallel port and finally a 5153 color monitor and original keyboard. This is a beautiful machine. In fact, it looks and works like a new computer!

Eventually I'll be adding a new XTIDE card to allow the use of a CF card slot installed into one of the expansion bay covers on the back of the computer. Unfortunately, that will use the last of my available upgrade slots, but the functionality will be increased. With that, I can just plug in my CF card and effectively, use it as an internal hard drive. I know the guy who makes and sells the XTIDE cards. His next revision is in the final testing phase right now, so it should be about another 60 days when the new cards will be shipped.

By formatting and partitioning a 1 Gig CF card, the 5150 will boot from several different versions of DOS, different versionns with shell programs installed like PB Navigator, and Menu Works as well as some of the self booting software titles like some of EA's games, all from the same card. Since the XTIDE has its own BIOS, it will also allow the user to decide which method to boot the computer, including the original floppy drives.

The addition of DOS shells along with running programs like Lotus 123 will and push the limits of RAM and processor on the system too, so any gains made by adding a math co-processor could be significant. I'm not talking pentium class performance, but still...

Please don't get me wrong. I also have an XT machine too, but that one is strictly a gaming computer and I'm not planning on using it for anything but gaming. However, you know how plans go.

There is one more point to make too. I am very disabled and have to use a power wheelchair for mobility. I only have one good arm, so I try to keep my activities arranged so that I can use my good arm for manipulating things around me for easier access. Being disabled also means that I am definitely not what you would call rich, so just going out to grab a few extra parts, like different hard drives, drive controllers, or even buying replacement processors is not that easy. I wish I could spend the money I want on rebuilding and refurbishing my old systems, but it's just not that easy. I do what I can afford at the time. So far, I think Ive done pretty well with these machines. They're both in great physical and working condition. The XT is not as nice looking as my PC, but hey; they're both great computers.

I'm keeping this list of instructions though just in case I decide to do something different later. Your recomendations just might come in handy later on.

Thanks for the info.

Joined: 03 Feb 2006 Posts: 488 Location: pennsylvanai

be aware that older versiuons of DOS have limitations
the first version that broke the 32 mb limit was dos 5.
did 2.10 supposedly had a 16mb hd limit ( so they say) but I set up a st-225 -21mb drive under dos 2.10
dod 3.2 was a dog, trying to upgrade to a newer dod resulted in a blank hd
but dod 3.1- was decent but limited
dod 3.30 was ok but had that 32mb limit. However unlike 3.1
dod 3.30 allowed you to make multiple partitions
At intel PRO in those days,
I took a state of the art 386-25
it had a st-251 and an esdi 660mb
and several floppies.
I made drives a-z. so with 3.30 you cannot use the entire drive.
I do not think multi-boot was possible then
avoid NEC and Compaq dod 3.31
it alloes drives larger than 32mb
but is non standard so other dod versions will not see that partition.

dos 4.00 was flakey dod 5 had some minor problems
and dos 6.22 never required an upgrade.
you can use the later EDIT.com from windows /dos

lits of little pitfalls.
there was a 534m limit on IDE drives that was bios related
I do not know how itn would affect a cf card on a ide/cf adapter.
scsi did not have that limit -- except the dos 16 ( or possibly 8 bit?)
Limit of 2048 megs ( 2g) this was a limitation of FAT adressing.

I would suggest looking for a copy of "as easy as" a lotus clone.
Lotus had copy protection and unless the original floppy was in the A drive, the program would not run
Ontrack did manager will overcome the drive size limitations easily.
But you MUST keep a bootable floppy handy as the driver files tend to get corrupted.
also in pc/xt days the mfm drive would suddenly become totally empty
there was no fix gfor this
and sopmetimes the drive would appear dead,.
this could be fixed by powering down and jiggling all the connectors.,
or pull them off and then on- especially the gold finger connectors on the hard drive.
as I said before do not use the original xebec ibm hd controller.
no matter how authentic you wish to be.

Joined: 02 Oct 2004 Posts: 377 Location: Stuttgart, Germany

Maybe eBay is a way to get the copro for less $$$. Just search for 8087.
This one goes for 12.50 (17.50 after shipping):
http://www.ebay.com/itm/Intel-8087-numeric-co-processor-/270807186287?pt=LH_DefaultDomain_0&hash=item3f0d5dbb6f