turek@brl-tbd.ARPA (C. A. Turek ) (07/09/86)
Here's a little gem for you hardware types. I have just spent a very exasperating day trying to upgrade a IBM PC-1 to handle a Bournulli Box and EGA. Both of these require the installation of the ROM BIOS upgrade for operation. So far nothing unusual. After pulling out the old rom, installing the new one, the system refused to do so much as a POST. The first sign of trouble was the lack of the cursor on the display. The system sets the screen to black, then NOTHING. I removed the EGA and the Iomega card and still no dice. I got out all the documentation for the adapter boards and double checked the switch settings with no luck. It just refuses to boot. I replaced the old rom and the system boots normally, although the Iomega and the EGA don't respond the system goes through the rest of the POST. Figuring that the new rom might be defective I tried it in a working system that is configured exactly the same, including the rom upgrade. No problems, the rom in question works without a hitch! I then tried the rom from the working PC in the flakey PC. Nada! Both of these systems were purchased at the same time (from IBM) and are configured as follows, any suggestions??? IBM PC w/64k system board, 8087 ( new 8088 also ) Seattle 256k Ram Board w/1 serial port (COM 1) AST MEGA-Plus w/384k installed, 1 serial port, 1 parallel port, clock IBM EGA with 256k module IBM Enhanced Graphics Display Iomega 10+10 (This is the half card w/o boot rom) 2 10 meg drives I've called the IBM Tech Rep in Baltimore and this is a new one on him but he's "checking the database" to see if it's happened before. Chris... ------------------------------------------------------------------------ Words to live by: "The check is in the mail." turek@brl.arpa Chris Turek Ballistic Research Lab SLCBR-TB-P Aberdeen Proving Ground, MD. 21005-5066
dale@wucs.UUCP (07/18/86)
In article <156@brl-tbd.ARPA>, turek@brl-tbd.ARPA (C. A. Turek ) writes: > > > > Here's a little gem for you hardware types. I have just spent a very > exasperating day trying to upgrade a IBM PC-1 to handle a Bournulli Box > and EGA. Both of these require the installation of the ROM BIOS upgrade > for operation. So far nothing unusual. > > After pulling out the old rom, installing the new one, the system > refused to do so much as a POST. The first sign of trouble was the lack > of the cursor on the display. The system sets the screen to black, then > NOTHING. > > > Both of these systems were purchased at the same time (from IBM) and are > configured as follows, any suggestions??? > > IBM PC w/64k system board, 8087 ( new 8088 also ) > Seattle 256k Ram Board w/1 serial port (COM 1) > AST MEGA-Plus w/384k installed, 1 serial port, 1 parallel port, clock > IBM EGA with 256k module > IBM Enhanced Graphics Display > Iomega 10+10 (This is the half card w/o boot rom) 2 10 meg drives > I installed a new ROM in a similar system except I was installing a fixed hard disk. The same thing happened to me. I discovered that the Seattle card was the culprit. I forget which chip but it was a 74LS74. I replaced it with a 7474 I had laying around and everything worked. This isn't exactly kosher but it works. DOES ANYBODY HAVE SCHEMATICS FOR THE SEATTLE CARD??? I've had this same problem happen to several cards especially when installing a hard disk controller. I'd like to find out why but don't want to take the time without a schematic. In case anybody is interested, Moterola has a PROM that is pin compatable with the ROMs used by IBM in the PC. I have used them to upgrade PC-1 to PC-2 and also for diagnostic purposes. (Did you know that the first set of boot diagnostics jump to the same location when detecting an error. At that location is a HALT!!!!!. Really helpful.) The part number for the PROM is MCM68766C35. Hamilton-Avenet stocks them (other places may have also, I have just dealt with Hamilton). The price should be $12-15. Dale Frye Washington University in St. Louis Computer Science Dept. PO BOX 1045 St. Louis, Mo. 63130