reza0@ihlpl.UUCP (H. Reza Zarafshar) (11/24/86)
Has anyone hookded an IBM-PC or AT keyboard to an AT&T 6300? I realize this question might have been asked before and the answer was no. But I really would like to know why this cann't be done so that I could ask some of the hardware experts to make a circuit to make the signals compatible if such a thing is possible and signal incompatibility is really the problem. Or maybe I have to reporogram the rom chips. Anyway, any help would be greatly appreciated. Reza Zarafshar, (312)979-5104 ihnp4!ihreza!reza0
wtm@neoucom.UUCP (Bill Mayhew) (11/26/86)
I don't think that merly rewiring the plug on an IBM keyboard is adequate to get it to work with the 6300. It looks like the baud rate is different to me, as I couldn't get it to work. Two of our 6300s here have replacement keyboards. One machine has an AT&T version of the Keytronic 5151 which even comes with a db-9 on the end of the cord. Another person got a keyboard form on of those places that sends you all those little postcards in a plastic bag. The latter keyborad was (I think) $149 and came with sidekick. It also had an IBM-like socket and a little extension cord to convert to the 6300's db9. Alas, the IBM socket did nothing when plugged into an IBM. If anybody really cares, send me mail, and I'll get you the name of the company; I forget it at the moment. By the way, one of my older 6300's that was in the days of 256K and 10 meg drives did indeed come with all the chips soldered to the board. The only socket in the machine was a blank one for the 8087. We flamed the AT&T salesperson, who produced the AT&T memory expansion card to get it up to 512K. I was suprised when I observed that the AT&T memroy card has to go in one of the slots that has the short socket near the front of the machine, although I don't see any reason why you couldn't use one of the expansion cards for regular pc-compatibles. --Bill (wtm@neoucom.UUCP)
jkg@gitpyr.UUCP (11/27/86)
In article <328@neoucom.UUCP> wtm@neoucom.UUCP (Bill Mayhew) writes: >We flamed the AT&T salesperson, who produced the AT&T memory >expansion card to get it up to 512K. I was suprised when I >observed that the AT&T memroy card has to go in one of the slots >that has the short socket near the front of the machine, although I >don't see any reason why you couldn't use one of the expansion >cards for regular pc-compatibles. I'm going to try to atone for my earlier faux pas concerning soldered-in chips by posting something useful. Can I be right just this once? Please? :-) The reason the expanded memory card uses the little slot is because the 6300 has an 8086, which requires 16-bit wide memory. The standard PC-compatible slots only support an 8-bit bus, so the additional 8 data lines (among other things) are brought out on the other slot. I think this also effectively halves your memory bandwidth because the bus only runs at 4 MHz. All memory accesses to the expansion memory will require the insertion of wait states to slow things down. Accesses to memory on the motherboard can be run at the full 8 MHz with no wait states. This is one reason why it is preferrable to put the full 640K on the motherboard. Jim Greenlee -- The Shadow...!{akgua,allegra,amd,hplabs,ihnp4,seismo,ut-ngp}!gatech!gitpyr!jkg Jryy, abj lbh'ir tbar naq qbar vg! Whfg unq gb xrrc svqqyvat jvgu vg hagvy lbh oebxr vg, qvqa'g lbh?!
dmt@mtunb.UUCP (Dave Tutelman) (11/29/86)
In article <328@neoucom.UUCP> wtm@neoucom.UUCP (Bill Mayhew) writes: > >I don't think that merly rewiring the plug on an IBM keyboard >is adequate to get it to work with the 6300. It looks like the >baud rate is different to me, as I couldn't get it to work. Actually, the whole protocol is a little different. A transposition cable isn't enough to solve the problem. >Two of >our 6300s here have replacement keyboards. One machine has an AT&T >version of the Keytronic 5151 which even comes with a db-9 on the >end of the cord. I've used the Keytronics. It's pretty nice, and I never noticed any incompatibilities. You might also try AT&T's new 302 keyboard, with better key placement and size than the original 301. I'm using it right now. >... =============================================== >By the way, one of my older 6300's that was in the days of 256K and >10 meg drives did indeed come with all the chips soldered to the >board. The only socket in the machine was a blank one for the >8087. We flamed the AT&T salesperson, who produced the AT&T memory >expansion card to get it up to 512K. I was suprised when I >observed that the AT&T memroy card has to go in one of the slots >that has the short socket near the front of the machine, although I >don't see any reason why you couldn't use one of the expansion >cards for regular pc-compatibles. Actually, the only reason is speed. The speed ordering is: - FASTEST - on the motherbaord. - SLOWER - The plug-in board from AT&T gives a wait-state on each access. - SLOWER STILL - Commercial plug-in boards using only the PC-bus. They don't use the full 16-bit capacity of the 8086. Remember that the PC and XT are 8088s with an 8-bit data bus. Thus all their memory accesses are single bytes. The 6300's speed advantage derives in part from a two-byte data bus, with the extra byte on the "short socket". > > --Bill > >(wtm@neoucom.UUCP) --------------------------------------------------------------- ---=== Dave Tutelman -------===== Physical - AT&T Information Systems ----------====== Room 1K218 ==--------======== 307 Middletown-Lincroft Rd. ====---========= Lincroft, NJ 07738 ============ Logical - ...ihnp4!mtuxo!mtunb!dmt ====== Audible - (201)-576-2442 ---------------------------------------------------------------