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101090 discussions

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

by pete＠dunnington.u-net.com

On Mar 22, 14:52, Philip.Belben(a)powertech.co.uk wrote: > Expansion box. > > The old PETs don't AFAIK have the internal expansion connector - they have an > edge connector sticking out at one side. Very useful for toggling RESET with a > pair of tweezers! Yes, I know :-) Mine has the edge connector, not the expansion block. > That aside, on this edge connector are brought out most of the block select > lines from the 74154 I mentioned in my previous post. In particular, brought > out are lines 1 to 7, 9, A and B. > > It takes only three four-input AND gates to re-encode any eight of these you > choose into three upper address lines for a 62256. Seems like the hard way to do it... > My suggestion is: disable the select to the upper 4K of memory within your PET, > and encode lines 1 to 7 and 9. This will give you 32K of main memory, several > spare 6550s, and 4K of RAM above the screen. Essentially, you will have a 4K > PET fully expanded. I was actually thinking of replacing the 74154 with a socket, to get access to all the signals I'd want -- I could enable (or not) all the RAM that way, and use the internal ROMs. It would only require one 22V10; and I would prefer to use several ROMs (probably 27256s) for the alternate BASICs. I'd take the data lines from the edge connector, probably. If you look at the PET circuit, you'll see the data lines to the edge connector are buffered, and the control to that buffer is hardwired (via AND gates and an inverter) to several of the SEL block selects from the 74154; similarly, the RAM buffers are hardwired to SEL0 and (via an OR, a NAND, and a link) SEL1. So you can't put replacement RAM on the expansion connector without doing something about that 74154... Plus, the SEL lines relevant to the ROMs aren't present on the edge connector, but they are on the 74154. -- Pete Peter Turnbull Dept. of Computer Science University of York

26 years

AXP vs VAX (was Re: Aaaaahhhh... 'Tis Good to be Back!!!)

by ethan_dicks＠yahoo.com

--- healyzh(a)aracnet.com wrote: > > Ow... that's scary. I am in the process of _finally_ building up this > > AXP133 "no-name" board... > Since you're running Sparc's with 64MB, to give you an idea of what I > consider acceptable performance, I don't consider Solaris 2.6 acceptable in > 64MB, but it's quite nice in 96MB on my Sparc 2. I don't consider 64Mb acceptable if I'm running CDE. It's horrible. Things are sluggish but not painful under OpenWindows. I'd run 96Mb if I could, but I don't have the Sbus expansion card. I used to use a Sparc 5/110 as my primary desktop machine at Lucent, and with 256Mb of memory the only ongoing problem I had was with starting up Netscrape - it took much more than a minute. Once I was in, things were ducky. I could even run ViCE at 200% 6502-emulation speed with no problems. > In the case of OpenBSD I was able to get a Tulip-based 10/100 NIC working > with no problem in the AS200. I *can not* get one working under OpenVMS, it > looks like I need a real DE500 to work under OpenVMS. I bought a real DE500 once, just for this box (not that it runs OpenVMS due to other driver issues). It never left the show with me; I think I set down the bag and walked off. Not the first time, but usually I remember while I'm still in the same aisle. > On the RAM, I *always* check for used True Parity 72-pin SIMMS when I'm > anywhere that has used RAM. Me too. I'm up to five pair of 16Mb and one pair of 4Mb. :-( > You're lucky. The AS500 requires custom RAM, the only way I'm going to get > it more memory is by spending about $500 :^( Ow! Speaking of custom RAM, I notice that on diagnostics, the IPX detects 33bit vs 36bit parity SIMMs. Are there any performance differences? I only have three or four 33bit 16Mb SIMMs. I was just wondering if there were any benefit to take these to 36bit. I plan to use the IPX as our primary DNS server at work, so enhanced reliability is a benefit. -ethan ===== Even though my old e-mail address is no longer going to vanish, please note my new public address: erd(a)iname.com The original webpage address is still going away. The permanent home is: http://penguincentral.com/ See http://ohio.voyager.net/ for details. __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com

26 years

OSI bliss...

by dogas＠leading.net

Wow. Hi everyone. A hot tip, a long drive, lots of digging, and a pocket full of kryptonite turned up an OSI C3C12 yesterday! It's a 4 component system including the CD2 8" floppys, a big CD23 Shugart SA4000 harddrive, and a Hazeltine terminal that's OSI branded (neat.) It sports a 17 slot backplane with a 525, 590, CSS cpu+ (that is cracked), and 3 522's now in it. I found another box of boards that had 2 510's (my favorite), a 555, 2 550's, 2 470's, and 3 520's, and a CA-18E ((on a 550 board)?) that hints at level III networking) Also got a bunch of software like os-65u v1.43 timeshare, ( w/mputil...) Looks like it can handle 3 users maybe. And there are boxes of disks I haven't even gone through yet. The documentation was a wonderful find too. Most of it is preliminary docs of things like the: Ohio Scientific Multiple User Computer System Manual C2-8p Users Manual C3 Setup and Operations Manual (with the C3 Utilities and Demo disks (!!!)) OS-DMS Shugart SA4000 servicing info OS-65u Ref Manual a *huge* binder of tech and sales newsletters and a real cool OSI Servicing Data book for *many* of the osi boards >from 470-594 and cii and cIII systems Then the ghost of classiccmp-past infused and led me back to a dark dusty workbench where I scored 3 boxes of molex connectors that I needed desperately. Oh, I found a Motorola EXORmacs system in the same pile too. yipee! My home is smaller. One happy ccmper signing off... ;) - Mike: dogas(a)leading.net

26 years

AXP vs VAX (was Re: Aaaaahhhh... 'Tis Good to be Back!!!)

by ethan_dicks＠yahoo.com

--- jmd <jmd(a)infinet.com> wrote: > Ethan > I have 1 DEC 205 NIC if you are interested. ISA slot. How much? -ethan ===== Even though my old e-mail address is no longer going to vanish, please note my new public address: erd(a)iname.com The original webpage address is still going away. The permanent home is: http://penguincentral.com/ See http://ohio.voyager.net/ for details. __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com

26 years

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 22, 0:51, Eric Smith wrote: > Chuck McManis asked: > > I'm confused, aren't these "fan out" units just hubs? > > Aaron Christopher Finney replied: > > These simply provide multiple ports on a single tap. I indicated my > > interest in them for the thick ethernet segment in my garage, as I only > > have 3 transceivers tapped into it at the moment. Physically, they just > > connect to the tapped transciever. > > Which, as Chuck suggests, is a effectively a description of a hub, albeit one > that has AUI interfaces rather than 10-base-T. Ethernet hubs are technically > multiport repeaters, and are subject to all of the topology and distance > limits of repeaters. I'm not sure these are repeaters, though. So a signal that's sent from a station on one of the AUI interfaces would go onto the wire, but I'm not sure that it would get back (directly) to the other AUI interface(s). Anyone know? -- Pete Peter Turnbull Dept. of Computer Science University of York

26 years

AXP vs VAX (was Re: Aaaaahhhh... 'Tis Good to be Back!!!)

by ethan_dicks＠yahoo.com

--- "Zane H. Healy" <healyzh(a)aracnet.com> wrote: > Good Grief! The most any Alpha on my home cluster has is 112MB and my best > Alpha only has 96MB because the RAM is so blasted expensive! I've found > that a Alpha with 80MB is about the same as a VAX with 16MB, and don't even > consider DECwindows in less than 80MB (and you won't see good performance > till 112MB). Ow... that's scary. I am in the process of _finally_ building up this AXP133 "no-name" board I bought a few years ago. Currently, it has 64Mb because parity 16Mb SIMMs are stunningly expensive. I lucked out at the Dayton Computerfest a couple of weeks ago and cleaned a vendor out at $15 per stick. Now my Alpha has 64Mb, my LX will have 64Mb and even my main SPARC-IPX. It's been a memorable experience. ;-) The Alpha has on it an older version of NetBSD. I'm considering upping it to the latest rev or going to RedHat. At the moment, I can't seem to get the 3C509 working, but I'd rather use something a little more advanced like a Tulip-based 10/100 NIC or even a 3C905C (since we have them around the office). One other piece of fun with this "no-name" board was locating compatible cache RAM. I stripped several 486s before I found a set of chips that would let the Alpha come up. The manual mentions a list of preferred vendors. Believe it. -ethan ===== Even though my old e-mail address is no longer going to vanish, please note my new public address: erd(a)iname.com The original webpage address is still going away. The permanent home is: http://penguincentral.com/ See http://ohio.voyager.net/ for details. __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com

26 years

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

by Philip.Belben＠powertech.co.uk

> I was never a service tech, but here in Ohio, the _only_ static PETs I've > ever seen were 6550-based. I didn't know there were any with 2114s until > I joined this list. It explains another Tramiel story. When the VIC-20 > was being designed, Jack told his engineers that he didn't care how much > memory the new computer used, but it had better take the 2114 chips that > C= had a warehouse full of. Never heard that story before. PETs up to and including 8096 used a couple or more of 2114s for video RAM, though. >> The old PETs don't AFAIK have the internal expansion connector - they have an >> edge connector sticking out at one side. Very useful for toggling RESET with >> a pair of tweezers! > > Don't miss! If I've got to the point where I need to hit RESET, it doesn't matter. Occasionally I corrupted I/O registers and disabled the interrupts that serviced the keyboard. You'd better not miss when toggling IRQ with the tweezers! 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 **********************************************************************

26 years

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

by ethan_dicks＠yahoo.com

--- Philip.Belben(a)powertech.co.uk wrote: > > > > > > Yes, I'm sure that's true. The 2114 PETs are rarer, but I can't see any > > If you used to service the things, I have to take your word for it, but I've > seen several with 2114s and I don't think I've seen any with 6550s. Oh well. I was never a service tech, but here in Ohio, the _only_ static PETs I've ever seen were 6550-based. I didn't know there were any with 2114s until I joined this list. It explains another Tramiel story. When the VIC-20 was being designed, Jack told his engineers that he didn't care how much memory the new computer used, but it had better take the 2114 chips that C= had a warehouse full of. > The old PETs don't AFAIK have the internal expansion connector - they have an > edge connector sticking out at one side. Very useful for toggling RESET with > a pair of tweezers! Don't miss! -ethan ===== Even though my old e-mail address is no longer going to vanish, please note my new public address: erd(a)iname.com The original webpage address is still going away. The permanent home is: http://penguincentral.com/ See http://ohio.voyager.net/ for details. __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com

26 years

need help reading a paper tape....

by acierno＠mindspring.com

Is there anyone out there who can help me. I have a paper tape (for the KIM-1) and I need it read. I dont care too much what format I get back - disk, paper print out, ect. would all be fine. I thought I had arranged to have it read by a commercial classic computer support person --- but they now tell me that it will be quite some time before they can get to my request. The tape has real historical value ( although not much real $$ value) and I would like to get it read as soon as possible. If you can help me or know of someone who can -- please e-mail me. thank you mark acierno ------- ICQ 40439199 http://www2.msstate.edu/~mja2

26 years

IBM 5150, am I nuts or what?

by ethan_dicks＠yahoo.com

--- Bob Stek <bobstek(a)ix.netcom.com> wrote: > For all the pissing and moaning today about IBM and Microsoft, let's face > it - the original IBM and then the XT are collectibles... > What can you do with them? Does the term "boat anchor" have any meaning for > you? I have a 5150 that is serving in its original capacity as a user-interface for a Northwest Instruments bus analyzer box. The analyzer has a 68000 pod and captures the last 4096 bus accesses. I used it once to prove to our engineer that his 68010 design on our VAXBI COMBOARD(R) was screwing up byte accesses (he swapped UDS and LDS causing byte reads to pick up whatever happened to be the last upper or lower byte through the buffers - writes worked perfectly because the 680x0 writes the same data to D0-D7 as D8-D15 on a byte access). The 5150 itself came with an IBM-badged Epson something-X-80 printer, an original mono card (the monitor is long since dead) and some form of multi-expansion card (not an AST six-pack, but something like it). It also has some form of 10-20Mb hard disk in it. I realize this isn't how IBM shipped them, but it is how Northwest Instruments did. ISTR the price paid way back when was $5K for the PC and $20K for the analyzer, but the analyzer price _might_ have included the PC. We boxed the whole thing up at work in a gutted VAX-11/725 cabinet. At one point, we used 11/730s as production machines (linking binaries for our product under a non-primary version of VMS) and it was cheaper to buy 11/725s and harvest parts than it was to buy individual boards for the 11/730 (and a lot cheaper than DEC maintenance). I don't have my working 11/725 anymore, but it was a fun machine when I had it. With a bit of boot tape optimization, it came up almost as fast as our 11/750. -ethan ===== Even though my old e-mail address is no longer going to vanish, please note my new public address: erd(a)iname.com The original webpage address is still going away. The permanent home is: http://penguincentral.com/ See http://ohio.voyager.net/ for details. __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com

26 years

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