ckp@grebyn.com (Checkpoint Technologies) (04/10/90)
In article <10715@cbmvax.commodore.com> andy@cbmvax (Andy Finkel) writes: >In article <1990Apr8.013940.12984@wam.umd.edu> ddev@wam.umd.edu (Don DeVoe) writes: >>as follows: "...It is also the first personal computer to have two >>additional processors - with the power of two additional personal computers - >>to manage the flow of information inside." Now consider: Do the Amiga's >>blitter, copper, etc. themselves have the power of additional personal >>computers??? Nope, they don't. The IIfx uses, I believe, two 6502 to > >The Amiga 500, 1000 and 2000 each have a 6502 as well as a 68000. The keyboard CPU is a 6502? Hmm, this is not what I remember. I thought it was a 6802; certainly comparable. If you have a A2090 or A2090A controller, you also have a Z80 CPU working as an IO processor. This is directly analagous to the Max IIfx's IO coprocessors.
ddev@wam.umd.edu (Don DeVoe) (04/10/90)
In article <19543@grebyn.com> ckp@grebyn.UUCP (Checkpoint Technologies) writes: > >If you have a A2090 or A2090A controller, you also have a Z80 CPU >working as an IO processor. This is directly analagous to the Max >IIfx's IO coprocessors. Hardly analogous. The IIfx comes with its coprocessors on board, whereas the 2090 (which works pretty poorly anyway, from what I hear) costs extra $$$, and certainly isn't standard equipment. This hardly invalidates Apple's claim... -- Don DeVoe ddev@epsl.umd.edu
phoenix@ms.uky.edu (R'ykandar Korra'ti) (04/11/90)
[Well, if you're going to get silly about it...] In article <10715@cbmvax.commodore.com> andy@cbmvax (Andy Finkel) writes: >The Amiga 500, 1000 and 2000 each have a 6502 as well as a 68000. The Commodore 64 with CP/M (Z-80) cartridge used the 6502 as an I/O processor. Add the 6502 in the 1541 disk drive and that's the same number of 6502 processors as the Mac has. Not that this entire discussion isn't terminally silly. :-) Did anybody else write patches to the C-64 CP/M BIOS to allow cursor movement? - R'ykandar. -- | R'ykandar Korra'ti | Editor, LOW ORBIT | PLink: Skywise | CIS 72406,370 | | Elfinkind, Unite! | phoenix@ms.uky.edu | phoenix%ms.uky.edu@ukcc.bitnet | | "Careful, mom, the toys are loose!" - from The Wizard of Speed and Time |
sam@ms.uky.edu (Michael W. Mills) (04/11/90)
ddev@wam.umd.edu (Don DeVoe) writes: >In article <19543@grebyn.com> ckp@grebyn.UUCP (Checkpoint Technologies) writes: >> >>If you have a A2090 or A2090A controller, you also have a Z80 CPU >>working as an IO processor. This is directly analagous to the Max >>IIfx's IO coprocessors. >Hardly analogous. The IIfx comes with its coprocessors on board, whereas >the 2090 (which works pretty poorly anyway, from what I hear) costs >extra $$$, and certainly isn't standard equipment. This hardly invalidates >Apple's claim... It isn't standard equipment an a regular A2000, just like the extras of the IIfx aren't standard on a regular Mac II. The 2090 (and now 2091) ARE, however, standard equipment on higher end amigas. (And the 2091 is a great improvement over the 2090 anyway.)
kosma%stc-sun@stc.lockheed.com (Monty Kosma) (04/11/90)
From: Don DeVoe <ddev@wam.umd.edu> Date: 10 Apr 90 16:37:45 GMT In article <19543@grebyn.com> ckp@grebyn.UUCP (Checkpoint Technologies) writes: > >If you have a A2090 or A2090A controller, you also have a Z80 CPU >working as an IO processor. This is directly analagous to the Max >IIfx's IO coprocessors. Hardly analogous. The IIfx comes with its coprocessors on board, whereas the 2090 (which works pretty poorly anyway, from what I hear) costs extra $$$, and certainly isn't standard equipment. This hardly invalidates Apple's claim... not if you buy an A2000HD or A2500 ... [does the a2091 have an onboard cpu?]...give me a break. This is just squabbling over inconsequentials. The IIfx has processors to do I/O control. So, what do you think the A2090/1 is doing? -- Don DeVoe ddev@epsl.umd.edu
ckp@grebyn.com (Checkpoint Technologies) (04/11/90)
In article <1990Apr10.163745.16255@wam.umd.edu> ddev@wam.umd.edu (Don DeVoe) writes: >In article <19543@grebyn.com> ckp@grebyn.UUCP (Checkpoint Technologies) writes: >> >>If you have a A2090 or A2090A controller, you also have a Z80 CPU >>working as an IO processor. This is directly analagous to the Max >>IIfx's IO coprocessors. > >Hardly analogous. The IIfx comes with its coprocessors on board, whereas >the 2090 (which works pretty poorly anyway, from what I hear) costs >extra $$$, and certainly isn't standard equipment. This hardly invalidates >Apple's claim... I wasn't trying to invalidate Apple's claim. And I still think the Z80 in the A2090 is analogous; it's doing an IO task with a general purpose 8 bit CPU. The IO processors in the Max IIfx are doing IO tasks with a general purpose 8 bit CPU. In the A2090, it's a Z80 and it's doing disk control. In the IIfx they're 6502s, and one's doing serial IO and I don't remember what the other is doing. The A2090 is an option card and the IIfx has their 6502's built in. Alright, there are differences, but I meant that the additional CPU's functions were similar, relating two different engineers' ideas on solving the same problem: relieving the main CPU of IO processing.
ckp@grebyn.com (Checkpoint Technologies) (04/11/90)
In article <14895@s.ms.uky.edu> sam@ms.uky.edu (Michael W. Mills) writes: >ddev@wam.umd.edu (Don DeVoe) writes: > >It isn't standard equipment an a regular A2000, just like the extras of the >IIfx aren't standard on a regular Mac II. The 2090 (and now 2091) ARE, however, >standard equipment on higher end amigas. (And the 2091 is a great improvement >over the 2090 anyway.) But the A2091 no longer has a Z80 CPU. It seems that when ST506 was dropped, the added CPU cost more than it was worth and took too much space on a board that also had to hold 2 meg RAM and a disk drive. SCSI is obviously easier to control, due to the disk drive intelligence that must be present anyway. And even the Mac IIfx doesn't have an IO CPU to control it's SCSI interface, though they have adopted DMA for the first time ever.
daveh@cbmvax.commodore.com (Dave Haynie) (04/12/90)
In article <19594@grebyn.com> ckp@grebyn.UUCP (Checkpoint Technologies) writes: >In article <14895@s.ms.uky.edu> sam@ms.uky.edu (Michael W. Mills) writes: >>ddev@wam.umd.edu (Don DeVoe) writes: >But the A2091 no longer has a Z80 CPU. It seems that when ST506 was >dropped, the added CPU cost more than it was worth and took too much >space on a board that also had to hold 2 meg RAM and a disk drive. Basically, with ST-506 out of the way (which is a dumb interface, not much different than a floppy disk interface), there was no longer any need for an intelligent IOP on the hard disk interface. The custom DMAC chip on the 2091 does the job much better than a general purpose CPU would. SCSI drives are intelligent as well, and they basically do the rest of the job the 2090's Z-80 was doing. I think you tend to find things moving in circles with respect to I/O processing. Step one is to have the CPU do most of the work, basically using real dumb I/O ports. The next step is to build an smarter I/O chip, something that'll handle the low-level protocols and just hand the CPU cooked bytes or words, possibly even via DMA. One step further and you add a dedicated I/OP to deal with the I/O chips. But with the dedicated IOP, you may find you can get away with real dumb ports once again. With enough work, though, the general purpose I/OP can be replaced with a real smart chip that does the job far better. At least until the next generation of I/OP arrives. Etc. All of which doesn't really matter than much. The important part is to have the solution, whether dumb I/O, smart I/O, or I/OP, match the problem you're trying to solve. -- Dave Haynie Commodore-Amiga (Systems Engineering) "The Crew That Never Rests" {uunet|pyramid|rutgers}!cbmvax!daveh PLINK: hazy BIX: hazy Too much of everything is just enough
urjlew@uncecs.edu (Rostyk Lewyckyj) (04/12/90)
I find it just a little ironic that CC= used the Z80 on the A2900, while Apple used a 6502 in the MAC fx. If you know some history you will remeber that the 6502 was created and manufactured by a C= owned company MOS, and whoever manufactures it probably still has to pay royalties to MOS, i.e. C=. Meanwhile the Z80 belongs to ZILOG, iif ZILOG still exists?,. So why did C= decide not to use one of its own chips, and Apple a competitor decided to use a C= chip :-), :-)? Really I think that the idea of using seperate intelligences, computers, for subsidiary cooperating functions such as i/o would be a very good thing. Perhaps then you could have really concurrent i/o , a la the big boys. These could be addons on controller boards. They would be controlles by seperate programs (see IBM channel control programs, or blitter control programs)