test-drb March 2000

test-drb@ccmp.vtda.org

150 participants
515 discussions

Are you sure the 6550 is dead? (was: Mos Technology RAM wanted)

by pete＠dunnington.u-net.com

On Mar 21, 16:45, allisonp(a)world.std.com wrote: > > > I would have thought a 2101 was far too small. These are 4kbit chips. > > Are these single voltage or multiple? 4k? 22pin? sounds like the > semi-4600 and NEC D410 parts, a 4k pseudostatic 200ns cycle and access > under 120ns. I've got a rat load of upd410s. The moto part number > doesn't compute though. uPD410 is 18-pin 0.3" width, 4k x 1, with one ~CE line (the MOS Technology MCS6550 has 2 ~CS and 2 CS lines and it's 0.4" wide). I can't find any data on a 4600 but I assume it's similar. If you're asking about the 6550 I'm looking for, yes it is single 5V rail, but it's 1k x 4 and it's not Motorola. In fact, I'm fairly sure no-one but MOS Technology made them. -- Pete Peter Turnbull Dept. of Computer Science University of York

24 years, 9 months

Televideo TS-802H available

by donm＠cts.com

A friend of mine has a Televideo TS-802H that he is looking to part with. I was familiar with the machine a few years back, and I'm sure that it is still in good shape. If you are interested, contact Dick Hubbard at 619-229-0955. He will be pleased to hear from anyone who might like the machine. - don

24 years, 9 months

Spartan emulator

by mgregory＠vantageresearch.com

I don't know how they got there, but I remember seeing a large pile of these Spartans at Active Surplus, on Queen Street in Toronto (well-known to any Hogtown hackers) in late '88 or '89. Given Active's inventory policy ("If you don't buy it, we'll leave it lying around") they may still be there. Cheers, Mark. -----Original Message----- From: Cameron Kaiser <ckaiser(a)oa.ptloma.edu> To: classiccmp(a)classiccmp.org <classiccmp(a)classiccmp.org> Date: Tuesday, March 21, 2000 4:48 PM Subject: Re: Apple Network Servers > >I'm also particulary impressed with the Spartan page on your site (for those >in the dark, this was a hardware add-on for the Commodore 64 that turned it >into an Apple II): I thought it was just a hardware emulator, but its feature >set was really greater than the sum of its parts. Fascinating! > >-- >----------------------------- personal page: http://www.armory.com/~spectre/ -- > Cameron Kaiser * Point Loma Nazarene University * ckaiser(a)ptloma.edu >-- SOFTWARE -- formal evening attire for female computer analysts. ------------ >

24 years, 9 months

Toggling in PDP-11 Bootstraps...

by pete＠dunnington.u-net.com

On Mar 21, 14:33, Aaron Christopher Finney wrote: > Thanks Pete, I'll give this a try when I get home tonight. And thanks for > putting the comments in as well! It's nice to see what's going on, that's > kind of what I'm after by playing around with this stuff this way. I've stuffed a few other things on my web site at http://www.dunnington.u-net.com/public/ODT/ A few of the files are bootstraps taken from handbooks or manuals, but several of them are little bits of nonsense I wrote when I first encountered an 11/23, with no OS. Remember I was a beginner and try not to laugh out loud :-) If you think the syntax is a little non-standard, it's because I had to write my own cross-assembler and I hadn't used MACRO-11 much then. No, don't ask me for the source. It was so awful I threw it away :-) -- Pete Peter Turnbull Dept. of Computer Science University of York

24 years, 9 months

Apple Network Servers

by owad＠applefritter.com

>::What "is" a network server 500, and what is the upgrade (very unlikely to >::be worth $200)? > >A Network Server 500 is one of Apple's two ill-fated Unix server models. Not to mention thge _very_ ill-fated Apple Networ Server 300, which never made it past the prototype stage. My web site, Applefritter, is hosted on one of these machines. "The ANS 300 had the same architecture as the 500 & 700, but was intended to be an easily rack-mounted unit intended for Internet/FTP/Mail/Web serving, departmental and small database servers, etc, and consequently less expansion. It has two removable drive bays and one fixed drive (behind the LCD). Much of the serviceability & security was abandoned for the sake of size. For instance, there is no obvious way to secure the drive bays, or the motherboard tray from being removed. The power supply is fixed and would be slow to field repair. The fixed hard drive mounted behind the LCD is very hard to reach, etc. The key lock on the front controls only the "on, lock, service" options, unlike the multiple key lock controlling those functions plus doors and security on the full size 500/700 units. These issues eventually ceased to be important, however, as the ANS 300 never shipped. "Code named Deep Dish, the ANS 300 is essentially an Apple Network Server without the large drive array. As a consequence, the computer is only four rack-units high. The logic board is in the bottom of the unit on a slide-out tray. There are two standard ANS removable trays on the right side of the unit's front. The Deep Dish also has one fixed internal drive, and the floppy drive is fixed, as well. Apple also had plans to produce an external drive array for the machine, reason for the ultrawide SCSI port above the PCI slots." If anybody wants more information, see <http://www.applefritter.com/prototypes/deepdish/>. Tom ------------------------------Applefritter------------------------------ Apple Prototypes, Clones, & Hacks - The obscure, unusual, & exceptional. ---------------------<http://www.applefritter.com/>---------------------

24 years, 9 months

Toggling in PDP-11 Bootstraps...

by pete＠dunnington.u-net.com

On Mar 21, 11:09, Aaron Christopher Finney wrote: > > Does anyone have any practical advice concerning this, something that > might save me a little time/frustration? At least to start with, I'd ignore the MSCP stuff and play with the 11/73 and RXV21. It's easier to see what's going on, since you can single-step and look at the RXV21 registers; MSCP is a relatively complex protocol which uses command buffers in memory, and the registers won't tell you much. > I'd like to be able to set up the simplest system possible and try to > toggle in a bootstrap. I've played with the ones on metalab (RX01, MSCP) > without much real success so far. Trying to boot from the RX01's using the > bootstrap code on metalab results in the drive access light coming on, but > nothing else happening. Sending a break stops at 1044 every time, the > contents of that register is 1776. Trying to boot from the Dilog scsi > device #0 (should be DU0, right?) just hangs (again using the MSCP > bootstrap on metalab). The MSCP bootstrap is well-commented, so I can see > what's going on there...a little hint or push may be all I need to be able > to modify it to work for me. The RX01 bootstrap is not commented at all, > unfortunately. An RXV21 (RX02) bootstrap is different from an RXV11 (RX01). Below is one for an RXV21. I also have quite a few little routines to do things like echo to the console, test/size RAM, dump memory, find CSRs, do serial port loopback tests, etc; all small enough to enter using ODT. Mail me if you want any... 1 000000 ; RXV21_boot From Microcomputer Interfaces Handbook 1983-84, page 484 2 000000 ; Use ODT to enter, then set RS=340, R6=1000, R7=1000, then P 3 000000 ; 4 000000 ORG O1000 5 001000 ; 6 001000 012700 MOV #O100240,R0 6 001002 100240 7 001004 012701 MOV #O177170,R1 ; RXCSR 7 001006 177170 8 001010 005002 CLR R2 9 001012 012705 MOV #O200,R5 9 001014 000200 10 001016 012704 MOV #O401,R4 ; track 1, sector 1 10 001020 000401 11 001022 012703 MOV #O177172,R3 ; RXDBR 11 001024 177172 12 001026 030011 BIT R0,(R1) 13 001030 001776 BEQ $-4 ; wait for TransferReq or Done 14 001032 100437 BMI O1132 ; branch if ERR set 15 001034 012711 MOV #O407,(R1) ; set DDens, Read, Go 15 001036 000407 16 001040 030011 BIT R0,(R1) ; wait for TR 17 001042 001776 BEQ $-4 18 001044 100432 BMI O1132 ; branch if ERR set 19 001046 110413 MOVB R4,(R3) ; give sector number 20 001050 000304 SWAB R4 ; swap track and sector 21 001052 030011 BIT R0,(R1) ; wait for TR 22 001054 001776 BEQ $-4 23 001056 110413 MOVB R4,(R3) ; give track number 24 001060 000304 SWAB R4 ; swap sector and track 25 001062 030011 BIT R0,(R1) ; wait for TR 26 001064 001776 BEQ $-4 27 001066 100421 BMI O1132 28 001070 012711 MOV #O403,(R1) ; EmptyBuffer (DDens) command 28 001072 000403 29 001074 030011 BIT R0,(R1) ; wait for TR 30 001076 001776 BEQ $-4 31 001100 010414 MOV R4,(R4) ; save sector number 32 001102 010513 MOV R5,(R3) ; set word count=256 33 001104 030011 BIT R0,(R1) 34 001106 001776 BEQ $-4 ; wait for done 35 001110 100410 BMI O1132 36 001112 010213 MOV R2,(R3) ; set address=0 37 001114 060502 ADD R5,R2 ; increment... 38 001116 060502 ADD R5,R2 ; ...address 39 001120 122424 CMPB (R4)+,(R4)+ ; bump R4 by 2 and clear all flags 40 001122 120427 CMPB R4,#3 ; sectors 1 and 3 get done 40 001124 000003 41 001126 003735 BLE O1022 ; loop if not finished 42 001130 012700 MOV #0,R0 42 001132 000000 43 001134 005007 CLR PC ; go to address zero 44 001136 120427 CMPB R4,#0 ; dummy operation, pipelined but not executed 44 001140 000000 -- Pete Peter Turnbull Dept. of Computer Science University of York

24 years, 9 months

Almost free 2-port and 4-port fanouts, IEEE 802.3 compliant, Ethernet Version 1.0 and 2.0 compatible AUIs

by pete＠dunnington.u-net.com

On Mar 21, 12:09, Mike Ford wrote: > >Perhaps someone can tell me, on list, why no one on this list has any > >interest in these. Maybe everyone is saving their money for iOpeners d8^) > > I don't have a clue what they are used for. I don't know either, but I might hazard a guess that they originated in the days of thick ethernet, when taps were expensive, and had to be fitted at specific intervals on the thick coax. Then perhaps it might make sense to connect two devices to one tap/transceiver. I'm just guessing, though. Now if they'd been the other "gender", so to speak -- ie, if they could be used to connect one device to two transceivers -- it would be tantamount to a bridge. Then I could probably use one as a media converter by adding both a 10base2 and a 10baseT transceiver, and link the 10base2 part of my home network to the 10baseT part without leaving a power-hungry repeater running all the time. I don't think they'll do that though. I once tried it with two transceivers back to back, and just got millions of collisions. -- Pete Peter Turnbull Dept. of Computer Science University of York

24 years, 9 months

Are you sure the 6550 is dead? (was: Mos Technology RAM wanted)

by edick＠idcomm.com

OOPS! I misread the previous post . . . it does say 1k x 4 bits. The only 22-pin 4K-bit sram I remember from those days is one from EMM-SEMI, but the number escapes me. Nevertheless, the only SRAM I remember in a 22-pin package other than the EMM-SEMI parts, was the 256x4 2101. There were plenty of non-multiplexed DRAMs in that package, but few SRAMs. If you have 22-pin parts and the memory diagnostic is failing on a 4K-byte boundary, it's likely the parts are something wierd. The conclusion that Philip has reached here is quite plausible. I'd explore his proposed solution before going any further. MOS Technology did build a few oddball parts, but I don't remember seeing any of their parts as being THAT odd. My MOS data books don't include any memory parts, though they did build some ROMs at that time. Dick -----Original Message----- From: Philip.Belben(a)powertech.co.uk <Philip.Belben(a)powertech.co.uk> To: classiccmp(a)classiccmp.org <classiccmp(a)classiccmp.org> Date: Tuesday, March 21, 2000 10:51 AM Subject: Are you sure the 6550 is dead? (was: Mos Technology RAM wanted) > >> I think the basic number you're looking for is "2101" from the same 1K >> series as the famous "2102" which is a 16-pin 1kx1 with separate in and out. >> The 2101's I have are not fast enough to meet the 200ns spec. However, not >> much of anything that was readily available at the time the PET model 2001 >> came out was that fast. Either it was quite a bit faster, e.g. 2147, 2115, >> etc, or it was slower, e.g. 2114, 21L02, TMS4044 etc, which were typically >> 450 ns at that point in time. Those 450 ns parts worked handsomely with the >> 1 MHz 6502. Perhaps you'd be able to use a 2101. > >I would have thought a 2101 was far too small. These are 4kbit chips. > >I agree 200ns probably isn't essential - my PET of that date uses 450ns 2114s. >On the 1MHz 6502 you have 500ns between the two clock edges that govern RAM >timing - one guaranteeing a valid address, the second latching in the data. > >(FWIW there were FOUR motherboard designs for the early PETs, based on all >permutations of 2114 or 6550 RAM and 2316 or 6540 ROM. Mine is late for an old >style PET, and has 2114 and 6540) > >>>> > One of the MCS6550 RAMs has gone west. Does anyone have a spare, or an >>>> > equivalent, for sale? It's a 22-pin 1024 x 4 200ns static RAM. >>>> >>>> I'll have to check the RAMs in the spare PET that I >>>> keep in the garage. Can't remember whether they're SRAMs >>>> or DRAMs in the bigger PETs. >>> >>>Only the oldest 2001-x PETs use those SRAMs. I guess it's time to build >>>that upgrade board (a PAL, a pair of EPROMS, and some 6264s, a 62256, or >>>some cast-off PC cache). > >That's right. When they revised the ROM code, they revised the motherboard so >that all ROMs were 2332s (and the sockets would take 2732s) and all RAM was >dynamic. > >The thing that bothers me is that it says 3071 bytes free. This is EXACTLY the >number of bytes free you get on a 4K PET. > >My advice - Identify the suspect pair of chips (remember these are 4-bit wide >parts) - I have the circuit diagrams if you want - and swap them with the >corresponding pair for the top 1k of RAM. You should then get the message "6143 >BYTES FREE" when you power up. (Or try swapping them with the video RAM - >you'll soon see if the chip is dead!) > >I suspect, however, you will still get 3071 BYTES FREE. > >Let me explain. On these early PETS the top four address lines come from the >processor and go straight into a 74154 decoder, AND NOWHERE ELSE. This outputs >sixteen block select lines - one for each 4k of memory. Your PET is failing >memory test at exactly the point where it passes into the second 4k block from >the first. > >In short, I think a failure at the block boundary is too much of a coincidence. >I'd trace out what this line is doing from the 74154 (there is only one, and >it's 24 pin, so you can't miss it!) to the RAM. Failing this, I'd suspect >something else in the chip select logic. (It could, of course be a failure that >affects a whole chip, but I'd try the other things after you've swapped RAM >chips if the BYTES FREE doesn't change) > >As I said, I can lend you my copy of the circuit diagrams if you haven't already >got one. > >Philip. > > > > >********************************************************************** >This email and any files transmitted with it are confidential and >intended solely for the use of the individual or entity to whom they >are addressed. If you have received this email in error please notify >the system manager. > >This footnote also confirms that this email message has been swept >for the presence of computer viruses. > >Power Technology Centre, Ratcliffe-on-Soar, >Nottingham, NG11 0EE, UK >Tel: +44 (0)115 936 2000 >http://www.powertech.co.uk >**********************************************************************

24 years, 9 months

Are you sure the 6550 is dead? (was: Mos Technology RAM wanted)

by pete＠dunnington.u-net.com

On Mar 21, 17:30, Philip.Belben(a)powertech.co.uk wrote: > I would have thought a 2101 was far too small. These are 4kbit chips. Correct :-) > I agree 200ns probably isn't essential - my PET of that date uses 450ns 2114s. Yes, I'm sure that's true. The 2114 PETs are rarer, but I can't see any reason to use 200ns devices, except that's what MOS Technology (who were largely owned by Commodore) were making. > (FWIW there were FOUR motherboard designs for the early PETs, based on all > permutations of 2114 or 6550 RAM and 2316 or 6540 ROM. I've got the schematics for all 4 types. They're almost identical except for slight differences in the memory decoding. > The thing that bothers me is that it says 3071 bytes free. This is EXACTLY the > number of bytes free you get on a 4K PET. > > My advice - Identify the suspect pair of chips (remember these are 4-bit wide > parts) Oh, I did that to check that it was definitely the RAM and not anything else, long before I posted my request. I could fix about anything else on the PET, but I draw the line at grinding the top off to poke at individual flip-flops in an IC :-) FWIW, the first job I had in computers/IT/whateveryoucallit was looking after (and repairing at component level) PETs and other micros, in 1981. The PET determines the RAM size by reading and writing a byte in every block and assumes it has found the top of RAM when it gets an error. It was just coincidence that one of the 5th pair was the one to go. So I now have a 7K PET, because I put the faulty IC in the top pair. It reports 6143 bytes free. -- Pete Peter Turnbull Dept. of Computer Science University of York

24 years, 9 months

Are you sure the 6550 is dead? (was: Mos Technology RAM wanted)

by Philip.Belben＠powertech.co.uk

> I think the basic number you're looking for is "2101" from the same 1K > series as the famous "2102" which is a 16-pin 1kx1 with separate in and out. > The 2101's I have are not fast enough to meet the 200ns spec. However, not > much of anything that was readily available at the time the PET model 2001 > came out was that fast. Either it was quite a bit faster, e.g. 2147, 2115, > etc, or it was slower, e.g. 2114, 21L02, TMS4044 etc, which were typically > 450 ns at that point in time. Those 450 ns parts worked handsomely with the > 1 MHz 6502. Perhaps you'd be able to use a 2101. I would have thought a 2101 was far too small. These are 4kbit chips. I agree 200ns probably isn't essential - my PET of that date uses 450ns 2114s. On the 1MHz 6502 you have 500ns between the two clock edges that govern RAM timing - one guaranteeing a valid address, the second latching in the data. (FWIW there were FOUR motherboard designs for the early PETs, based on all permutations of 2114 or 6550 RAM and 2316 or 6540 ROM. Mine is late for an old style PET, and has 2114 and 6540) >>> > One of the MCS6550 RAMs has gone west. Does anyone have a spare, or an >>> > equivalent, for sale? It's a 22-pin 1024 x 4 200ns static RAM. >>> >>> I'll have to check the RAMs in the spare PET that I >>> keep in the garage. Can't remember whether they're SRAMs >>> or DRAMs in the bigger PETs. >> >>Only the oldest 2001-x PETs use those SRAMs. I guess it's time to build >>that upgrade board (a PAL, a pair of EPROMS, and some 6264s, a 62256, or >>some cast-off PC cache). That's right. When they revised the ROM code, they revised the motherboard so that all ROMs were 2332s (and the sockets would take 2732s) and all RAM was dynamic. The thing that bothers me is that it says 3071 bytes free. This is EXACTLY the number of bytes free you get on a 4K PET. My advice - Identify the suspect pair of chips (remember these are 4-bit wide parts) - I have the circuit diagrams if you want - and swap them with the corresponding pair for the top 1k of RAM. You should then get the message "6143 BYTES FREE" when you power up. (Or try swapping them with the video RAM - you'll soon see if the chip is dead!) I suspect, however, you will still get 3071 BYTES FREE. Let me explain. On these early PETS the top four address lines come from the processor and go straight into a 74154 decoder, AND NOWHERE ELSE. This outputs sixteen block select lines - one for each 4k of memory. Your PET is failing memory test at exactly the point where it passes into the second 4k block from the first. In short, I think a failure at the block boundary is too much of a coincidence. I'd trace out what this line is doing from the 74154 (there is only one, and it's 24 pin, so you can't miss it!) to the RAM. Failing this, I'd suspect something else in the chip select logic. (It could, of course be a failure that affects a whole chip, but I'd try the other things after you've swapped RAM chips if the BYTES FREE doesn't change) As I said, I can lend you my copy of the circuit diagrams if you haven't already got one. Philip. ********************************************************************** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This footnote also confirms that this email message has been swept for the presence of computer viruses. Power Technology Centre, Ratcliffe-on-Soar, Nottingham, NG11 0EE, UK Tel: +44 (0)115 936 2000 http://www.powertech.co.uk **********************************************************************

24 years, 9 months

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test-drb March 2000