wordproc@ucf-cs.UCF.EDU (wordproc) (12/09/89)
I have seen the innards of a Model II and a Model 16 on numerous occasions,
either to work on them or whatever.
The other day I saw a Model 12 with the back opened up, and was amazed at the
fact that it did not resemble either the II or the 16 internally! The boards
and slots are mounted horizontally like the shelves in a bookcase rather than
vertically as in the II and 16 machines.
Does the 12 take the same boards (hard drive controller and so forth) that the
II and 16 take? Why the different configuration?
Seems like a good way to create problems with cards
over a long period of time, with card bending and warpage and so forth.
___________________________________________________________________
_________ /
Marcus Clenney ___ ___ /___ ___/ ________ /
U. of Central Florida / | / | / / / ______/ /
Dept. of Computer Science / /| | / /| | / / / / /
Orlando, FL 32816 / / | |/ / | | / / / /_____ /
wordproc@ucf-cs.ucf.edu /_/ |___/ |_| /_/ /_______/ /
____________________________________________________________/bill@bilver.UUCP (Bill Vermillion) (12/10/89)
In article <1392@ucf-cs.UCF.EDU> wordproc@ucf-cs.UCF.EDU (wordproc) writes: > >I have seen the innards of a Model II and a Model 16 on numerous occasions, >either to work on them or whatever. > >The other day I saw a Model 12 with the back opened up, and was amazed at the >fact that it did not resemble either the II or the 16 internally! The boards >and slots are mounted horizontally like the shelves in a bookcase rather than >vertically as in the II and 16 machines. > >Does the 12 take the same boards (hard drive controller and so forth) that the >II and 16 take? Why the different configuration? > >Seems like a good way to create problems with cards >over a long period of time, with card bending and warpage and so forth. The 16 (sometimes called the 16a) was derived from the model II chassis. The boards were vertical. And they are held in place by one metal bar with slits and a rubber bumper. (I just double checked as I have my 16 apart at the moment). When the 16 came out the only memory boards were 256k. With the bus structure you could get 512k in a 16 and have two users. The 12 went to a bus with two more slots, and the 16B and the 6000 uses the bus structure there. The horizontal bus mounting is more secure and there are no problems with flexure and shorting. This node is running on a 6000 and I have a 1 meg board in it that is a 512 piggybacked with the other meg, to give me 2 megs of system memory with the mmu upgrade. (My 2 meg board is a bit sick at the moment) By going to the additional spaces you could then put in the additional serial ports and have room for the Bernouli box. Scrap the Bernouli and you can have another 3 port card for 9 users. (Over 9 users you go to the Model 12000, which is a modified Model II box with an extended bus structure. This requires a custom kernel - and is expensive. The "12000" is made by Snapp (or was) and will support 15 users. He can also hang about 8 250meg drives off the system if you really want). So the additional bus structure is a plus and is better. However more boards caused a cooling problem, and some B's with the turbo mods sound like a fan factory - there are 3 fans in those systems. With a 6000's bus structure you can go to the full 4 megs of accesible RAM, run 6 users, and a B'box. When I had the 1 meg card in the 16 I had to put a fan on top blowing down to keep the board cool. The 6000 cooling design is also much better - if you don't mistakenly leave the back cover off. -- Bill Vermillion - UUCP: {uiucuxc,hoptoad,petsd}!peora!tarpit!bilver!bill : bill@bilver.UUCP
doug@letni.UUCP (Doug Davis) (12/10/89)
In article <1392@ucf-cs.UCF.EDU> wordproc@ucf-cs.UCF.EDU (wordproc) writes: >I have seen the innards of a Model II and a Model 16 on numerous occasions, >either to work on them or whatever. > >The other day I saw a Model 12 with the back opened up, and was amazed at the >fact that it did not resemble either the II or the 16 internally! The boards >and slots are mounted horizontally like the shelves in a bookcase rather than >vertically as in the II and 16 machines. > First of all there are 6 machines in the same family, The models are 2, 12, 16A, 16B, 16B+, and 6000. The model's 2 & 16A had vertical card cages, the 16B[+]'s and 6000's had horizontal card cages. The model 12 however had no card cage, a card cage "upgrade" was offered for model 12 users that wanted to run XENIX or use the visicalc ram board, this effectivly turned the machine into a 16B. Since 16B's were really model 12's with factory installed card cages. 16B+'s were 16's with one floppy drive removed and a 15meg hard drive in it's place. This machine had a special hard drive card with both the interface and controler on the same board. This is unlike the normal hard drive board that was just an interface to the hard drive controler which existed inside the case of an external "primary" hard drive. Yes the original models had a slight heat problem corrected by a fan that was installed by the local service folks. This was commonly called the "turbo-fan mod" Later machines, and all the B+'s and 6000's came out with a factory installed fan that did the same job. >Does the 12 take the same boards (hard drive controller and so forth) that the >II and 16 take? Why the different configuration? Obviously the z80 CPU, SIO, FDC, and Memory boards won't work in a 16B or 6000 since the Z80/memory, etc al. is on a board of it's own. For this reason the 16B/6000 machine had several more free card slots. >Seems like a good way to create problems with cards >over a long period of time, with card bending and warpage and so forth. Unless your machine has the "turbo-fan mod" you are very likely to run into all sorts of problems, the least of which is card warping. doug "These opinions are my own and not Radio Shack's, who would like to forget that they once sold machines that were not IBM compatable. Even though they were faster, didn't have segment registers, etc..." -- Doug Davis/1030 Pleasant Valley Lane/Arlington/Texas/76015/817-467-3740 {texsun, motown!sys1, uiucuxc!sys1 lawnet, attctc, texbell} letni!doug
uhclem@trsvax.UUCP (12/11/89)
<> B>Does the 12 take the same boards (hard drive controller and so forth) that the B>II and 16 take? Why the different configuration? Yes. The CPU/RS-232, Memory, FDC/Printer boards from the Model II/16 are consolidated on a main board. The card cage needs only a Video/Keyboard adapter to be useful. The Video/Keyboard and all other add-on cards are the same as those that would go in a II/16, but now you have more room for them. B>Seems like a good way to create problems with cards B>over a long period of time, with card bending and warpage and so forth. Actually lack of heat-rise capability is the main problem with horizontal mounting, and since no one learns from history, IBM used the same strategy in some of the PS/2 systems. A user can even create these problem conditions with a plain old PC by running it on its side. Better have a good fan. <My opinion, and not that of my employer, Mr. "Heat flow? What's that? (TM)".> "Thank you, Uh Clem." Frank Durda IV @ <trsvax!uhclem> ...decvax!microsoft!trsvax!uhclem ...sys1!hal6000!trsvax!uhclem