Well, my waiting paid off. I picked up a Tektronix 4052 along with a Tek 4631 hard copy unit and custom metal cabinet late last year from a guy selling surplus medical school equipment.
The 4052 had three missing keycaps and that was very difficult to remedy, but found an ex-Tek employee who had the keycaps I needed! Also a bunch of program tapes and several ROM cartridges. I now have the Character Set ROM and Signal Processing #2. The 4631 had paper too old to use but I found some on the internet for $10! Also, after about a dozen printouts, the main drive belt fell apart. Even with the service manual, finding a replacement was very difficult. Fortunately the service manual listed the number of teeth and length of the belt, so I was able to get one from Stock Drive Products. I also located the service manuals and found a 4662 multipen plotter on EBAY.
I revived many of my old 4051 programs from the '70s, except for the ones that use the CALL "EXEC" command :( including my music playing program in 6800 assembly language.
I even modified a Kraft PC joystick to plug into the 4052 joystick connector - works great, played one of the startrek games for the 4051 that supported the joystick.
I also found and won a 4054 on EBAY early this year! This machine had been auctioned from Caltech. This machine was listed as not working. After some cleaning, I decided to try unplugging and reseating all the chips in sockets. I found one of the 16K bit DRAMs was bad, bought a 64Kbyte set to upgrade the memory to the 128KByte maximum and got the machine running again! Then I tracked down a malfunctioning opamp in the tape drive board and loaded some of my revived programs.
Wow - the 19" direct view screen is incredible compared to the 12" flat CRT screen in the 4051/52. Although it is not flat, it has much more detail - I can see why it was preferred for CAD. Amazing how Tektronix had the higher resolution completely compatible with the old software. The 4631 hard copy made an incredible printout.
Spurred on by the article at computergarage.org on using 4051s in Battlestar Galactica, I decided to try to write a short program to display a squadron of Battlestar Galactica Vipers on patrol. Using the image in the computergarage article, I printed the image on my inkjet, wrote a short digitizer program for the plotter and used the 4052 to digitize the outline of the viper in the picture. This is saved in a single array, then using Tek graphics WINDOW and VIEWPORT commands I draw the array with a single DRAW command, move the origin, resize the window and draw again. The same display on the 4054 is noticeably sharper than the 4052. By changing the DRAW command to a PLOT command, I'm able to plot the program to the 4662 - that's what I loved about the Tek PLOT 50 language.
I'm still looking for someone with information on the CALL "EXEC" command and the 'newer' 4052/54 bitslice machines.
Philip Belben was correct about the increased speed - some of my 4051 benchmarks run 10X faster on the 4052 and 4054. The "A" rev 4052A and 4054A added a TI GPIB chip to increase the GPIB speed further, and added a couple of other commands.
The 4054 added a "refresh cursor" that could be controlled with the built-in thumbwheels in the keyboard. There was an Option for REFRESHED GRAPHICS that expanded on that concept and added an 8X300 coprocessor board with refresh graphics memory to have a whole graphics image be drawn without "storing" the image on the screen. Apparently my machine left the factory with that option - but the board is no longer there. Love to hear from someone that had that option board.
Monty McGraw
From: Jay West <west(a)tseinc.com>
>It does appear to be an S-100 system. I'm not qualified to say that
since I
>am not into S100 stuff, but the cards inside it have 50 pins per side,
and
>it looks like the pics I've seen of S100 stuff.
It is. Sounds like a Z100 (Z110 and friends).
>The keyboard is missing the F12 key, and there is indeed a composite
video
>out rca jack. Right beneath it is a DB9F, from a quick look at the cable
>internal I'm guessing it is mono out. There's also about 20 punchouts on
the
It's mono. There was a matching tube but any B&W monitor will work.
Allison
From: Jeff Hellige <jhellige(a)earthlink.net>
>
> Don't the VT220 and VR201 share some parts as well? My VR201
>got dropped a while back and that's the reason my DECmate isn't up
Not really.. The tube is the same and maybe peice parts but ones a
basic monitor and the other a complete CRT system.
Allison
From: Tony Duell <ard(a)p850ug1.demon.co.uk>
>> I'm not sure about the DECmate III, but I know the II shares
>> a few parts with the VT220 terminals. It also shares it's case with
>
>Apart from the LK201 keyboard, and obviously standard electronic parts,
>what other items are common between the DECmate II and the VT220?
CRT {assuming VR201}, and not much else. Though DecmateII/III does
VT100/VT220 emulation.
>I know the 'bow rather better than the DECmate, and I'd consider that
>that machine has rather more in common with the VT100 than the VT220.
For
>example, the only 2 custom chips in a 'bow are the video timing chip and
>video path chip on the motherboard, and those are identical to the chips
>in a VT100.
Sorta. sorta like saying all Z80 machines run CPM, not much commonality
in a real sense. The chips are low level video timing and interface and
do
not really define VT100 or VT220 directly.
The point being is VT100 uses 8080 or 8085 for smarts, VT220 uses 8051
and DECmate uses the COMS PDP-8 chip for the smarts.
Allison
On December 29, Jay West wrote:
> I love my HP 1631D logic analyzer, but it takes up way too much real estate
> on my bench. I'd like to get a mobil cart for it, but virtually all the
> scopecarts I've seen (like the tek 200) are for small scopes & such... the
> 1631D analyzer is 16.5 inches across the middle, and 17 inches across the
> front (the bezel sticks out a bit on each side). Would anyone have a scope
> cart (like a tek 212 or similar) that is for wider instruments that is
> excess and would consider selling/trading?
>
> Second, I'm looking for various disassemblers for the 1631D... these came on
> 3.5 floppy, but I'm not sure what all disassemblers were available for it.
> Anyone got this software laying around?
I didn't think the 1631D had a floppy drive...? I had an HP 54201
oscilloscope for a while; it was my understanding that the 1631D was
basically a 54201 scope with an additional logic analysis module.
I've been shopping around off & on for a new logic analyzer...would
you recommend the 1631D?
-Dave McGuire
From: Jeff Hellige <jhellige(a)earthlink.net>
> I believe it was DEC's first microprocessor based PDP-8
>family machine, followed not long after by the DECmate series.
Correct, effectively decmate-I the VT52based version was the first
and second was VT100 based then decmate-II/III.
>Reason for introduction: Using TTL MSI and LSI components, DEC could
> pack a system into the vacant space in a standard terminal
case,
> allowing PDP-8 systems to compete with personal computers in
the
> small business and office automation market. This was a
natural
> follow-on to the desk-mounted workstation configurations in
which
> the PDP-8/A was already being sold.
Actually before 1980 there were very few "personal" computers so the
VT78 was ahead of the pack somewhat.
>Compatability: The Group I OPR combinations RAL RAR and RTL RTR are
> no-ops. Unlike all earlier PDP-8 models, autoindex locations
> 10 to 17 (octal) only work in page zero mode; these operate
like
> all other memory locations when addressed in current page mode
> from code running on page zero. Other than this, it is fully
> PDP-8/E compatable, even at the level of I/O instructions for
> the standard periperals; this was the last PDP-8 to offer this
> level of compatability.
The 6120 chip also had this and improve it a little but they were
actually the
end of the PDP-8 family line!
> the terminal. The console (device 03/04) and the serial ports
> (devices 30/31 and 32/33) are compatible with the M8650 KL8E,
> with the latter extended to allow software controlled baud rate
> selection. There are two parallel ports; device 66 (compatible
> with the M8365 printer controller) and device 47, compatible
with
> the nonstandard port on the M8316 DKC8AA. There is also a
100Hz
> clock compatible with the clock on the M8316 DKC8AA.
This is critical to most programs that would run on discrete PDP-8
systems
would run on the VT78 where the later decmates had a sorta/nearly but not
quite terminal emulation leading to OS/278 varient of OS-8. The
emulation
or existance of KL8e TTY interface at 3/4 was a defining standard for all
PDP-8 software that used a terminal interface.
Allison
While browsing through my usual electronics surplus haunts today in St.
Louis, I came across the following items for sale in a local shop. I have no
interest in them, but thought someone here might? If so, email me off-list.
Heath Computer Systems model H-101-20. This system looks vaguely like an
HP85 case, but no internal monitor. Might be pre-PC, but could be an x86 dos
system too - I have no idea.
Radio Shack DWP-210 printer. Has a manual with it.
Neither of these items had a price tag on them yet, but from past experience
I'd say this store would likely be tagging it around $40 for the puter and
$15 for the printer - I'm just guessing here. Don't know if either item
works, but I wouldn't mind going back and testing if someone can tell me
what to test on them. If anyone is interested, let me know off list what
your target and max price is and I'll go haggle for ya, or if you'd prefer,
put you in contact with the store directly. I wouldn't tack on any
additional cost except whatever shipping costs to you.
Regards,
Jay West
From: Joe <rigdonj(a)intellistar.net>
>take a soft-sectored disks and add more holes to it and see if it would
>work? I don't know how critical the spacing would be.
You would have to make an indexing punch, accurate to about 1-2% would
be adaquate. The media is otherwise standard 360k DD.
An alternate approach is to create a logic element that is synched to the
index hole and provides 10 false index marks that corospond to the
sector holes. A better drive like teac fd55A or B would work fine as
their speed is likely more stable than the old SA400s.
Years ago I did something similar to the NS* MDS-A controller to fake it
so the indexhole (present in both hard and soft media) was the start and
the
Index sync logic would free run on finding the index hole. Mostly worked
though I didn't try to hard to go further.
Allison
From: Jeff Hellige <jhellige(a)earthlink.net>
> The DECmate II is an interesting beast, but unfortunately it
>shares the hardware incompatabilities of the original DECmate, though
>it 'improves' on them. I have a II that is pretty loaded, with the
One that it makes worse is the terminal emulation. Terminal interrupts
are not supported in the same way as is TTY at 03/04 so the KL8e
emulation is poor except for the most simple programs that poll
the IO.
The improvements is 32KW of ram (32kw for pannel mode as well)
the possibility and support for a hard disk is nice. It's also faster
though the DMIII is fasest of the lot.
>working again. It sounds like from a software compatability point
>that the VT78 might be the better choice for a micro able to run
>standard PDP-8 stuff.
It's closer but the RX01/2 IO is somewhat different than the omnibus
companions.
Also the chip versions while very close to PDP-8 are not exact for timing
and OPR/ IOT instruction microprogramming is slightly different.
Allison
A friend of mine who's just beginning to collect found an NCR
Decision Mate V but no K-B. She tried an XT one and got a
"keyboard error" so it is working. The info I found on it says it's
a CP/M-DOS hybrid needing a special DOS version or CPM 2.2
Anyone out there with a spare keyboard or know a possible
substitute ? I understand it had 22 function keys (???) and a
QWERTZ layout. If so she'd also likely need a manual.
Any further details would also be appreciated. Thanks
larry
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