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#132488 - 10/05/06 09:36 PM Who knows what I'm talking about?  
JoeTestingEngr  Offline
Member
Joined: Nov 2005
Posts: 782
Chicago, Il.
Just curious as to how many know what the following applies to:

60127
00377

or

60136
00377

And for a totally unrelated follow-up question:

Does anyone out there still play around with Commodore 64s. I still have the User's and Programmer's Reference Guides, and "Mapping the Commodore 64". The Programmer's Reference included schematics and I got the Sam's Photofact for the pathetically slow serial disk drive. To this day, I'm amazed at the efficient use they made of 64K of address space.

I'm digging it out of the mothballs now because I think my 4 year old angel would get a kick out of it. The box talked quite well without adding hardware. There was a "Word Wizard" program that would have it pop up and ask you to spell words to progress through the game. Does anyone remember other educational programs that were available for it?

Joe


Tools for Electricians:

#132489 - 10/05/06 10:31 PM Re: Who knows what I'm talking about?  
Bill Addiss  Offline
Member
Joined: Oct 2000
Posts: 3,875
NY, USA
Joe,

I had several of those and hundreds of programs. I think everything was already given away or trashed, but if I find anything I'll let you know.

Bill


#132490 - 10/06/06 07:12 AM Re: Who knows what I'm talking about?  
Kenbo  Offline
Member
Joined: Apr 2006
Posts: 233
Scotland
To me those look like eprom chip numbers.

I still have my old sinclair spectrum and loads of games on tape. But I do not have a tape player [Linked Image]

Just remember getting frustrated waiting for 10 mins to load in a game only to find the the volume was set too low and it didnt load [Linked Image]


der Gro├čvater

#132491 - 10/06/06 10:13 AM Re: Who knows what I'm talking about?  
pauluk  Offline
Member
Joined: Aug 2001
Posts: 7,520
Norfolk, England
Quote
ust curious as to how many know what the following applies to:


Well, if they're octal numbers then 377 represents the highest value you could store in a single byte (i.e. 255 decimal or FF hex).

I can't think of anything specific relating to the other numbers. [Linked Image]


#132492 - 10/07/06 10:18 AM Re: Who knows what I'm talking about?  
JoeTestingEngr  Offline
Member
Joined: Nov 2005
Posts: 782
Chicago, Il.
They're definately Octal. I'll add that 601xx is a number that is stored in location 376. This should give you a good start. I guess that about all that we use Octal for these days is aircraft transponder codes, with 1200 being the most commonly used Octal number.

Eproms were usually the 27xx(x) series. I think I remember seeing some 2708s and mostly 2716s when I started working on mini computers. Now, it's rare to see less than a 27C256. I also vaguely remember that TI's 2716 was different than everbody else's and that they made a 2516 that would swap out OK.

I love thinking back to the days when I slid that "Mini'Meg", 1 MB, 1/2 Mword, into the 1st or 2nd slot of a "Point 4" CPU. Last month, I slid a 1GB MicroSD, smaller than my thumb, into the new phone. We would've needed a trailer for that in '81.

Kenbo, I ordered a Sinclair ZX-80, just for the fun of building it. They sent me an assembled one because they were out of kits. It was a piece of garbage.

On the C64, I built my own interface so that I could use my own tape recorder to load and save programs. I do remember having to play with it a while to find the sweet spot for levels.
Joe

[This message has been edited by JoeTestingEngr (edited 10-07-2006).]


#132493 - 10/07/06 08:44 PM Re: Who knows what I'm talking about?  
gfretwell  Offline


Member
Joined: Jul 2004
Posts: 9,060
Estero,Fl,usa
When I started working with computers, bits were stored in ferrite rings strung on wire. 2 meg disk drives were the size of a washing machine and leaked oil on the floor.


Greg Fretwell

#132494 - 10/08/06 01:39 AM Re: Who knows what I'm talking about?  
JoeTestingEngr  Offline
Member
Joined: Nov 2005
Posts: 782
Chicago, Il.
I figured you would give the answer Greg. I loved working on the machines with core memory. The drivers were getting a little hard to find at the time. We bought up al the TI 75???s we could find at the time so we wouldn't run out. I still remember having to fix a Data General 1200 or 1220 CPU with core memory. It couldn't load the diagnostics from mag tape. I pot in a good CPU, loaded from mag tape and shut down. Then I swapped in the bad CPU and powered up. The diagnostics were still in core. The Mini-Megs couldn't have pulled that one off.

On the original question, does IPL bootstrap or BZUP ring a bell with anyone?
Joe

[This message has been edited by JoeTestingEngr (edited 10-08-2006).]


#132495 - 10/08/06 12:12 PM Re: Who knows what I'm talking about?  
gfretwell  Offline


Member
Joined: Jul 2004
Posts: 9,060
Estero,Fl,usa
I was an IBM brat, we never saw much Data General stuff. When I moved to Florida in 1984 one of my first tricks was to find and fix a broken weld in a core storage array in a 3890 check sortor (to get one of those million dollar "captures" in on time). It got me some attention.
Nobody had an array in stock, it would have ended up coming from old equipment.
The core was the same as what they used in the 360 mod 25 and 30 and I was region specialist on those boxes although I had never really seen a 3890 before. Core is a very structured matrix and as soon as you develop the failing pattern you can usually point to the bad weld, even if you can't see it. I ended up using a paperclip on the end of a fine tip soldering iron to dab a bit of solder on it. 5 minutes later they were running checks.
I started on 1401s and "greasy gear" machines in 1966. By the 80s the writing was on the wall that actually fixing computers was a dead end job and I got into building computer rooms, then that became a dead end job when computers were shoved in closets or under desks.
I still like the days when it was 4 gates per card and a computer had thousands of cards in them. THAT is fixin'.
I/O was fun in those days too. No electronically controlled stepper motors. They used hydraulics to move read heads and paper.


Greg Fretwell

#132496 - 10/08/06 01:40 PM Re: Who knows what I'm talking about?  
JoeTestingEngr  Offline
Member
Joined: Nov 2005
Posts: 782
Chicago, Il.
OK, forgive me if I'm a little fuzzy here. I believe that IPL was Initial Program Load and BZUP was Block Zero Utility Program. We had to get that 400 octal block of data into memory to start up the operating system. We would use the front panel toggle switches set to 376 and press a momentary "Examine" toggle. Then we would set the switches to 601xx and press the momentary "Deposit" toggle. This was a "No Input Output Start" command to device number xx. This was the device number of a mag tape, hard disk, paper tape, or other controller. Then we would set the switches to 377 and press the momentary "Deposit Next" toggle. This was just a jump back one instruction. We would then set the switches back to 376 and press the momentary "Run" toggle. This caused a transfer of the first block of operating system data into memory until the little toggle routine loop got overwritten by the program. The data then written into 376 and 377 would probably be considered a cold start vector. It would point to a much more elaborite program, just loaded into Block 0, to load more of the operating system.
Joe

[This message has been edited by JoeTestingEngr (edited 10-08-2006).]


#132497 - 10/09/06 01:19 PM Re: Who knows what I'm talking about?  
gfretwell  Offline


Member
Joined: Jul 2004
Posts: 9,060
Estero,Fl,usa
The only IBM machine I remember with a hand loaded bootstrap was the 360 mod 25. It was to load the microcode (BIOS to PC guys) Those were core machines so you didn't have to put it in often but when it was lost it took a while. This was something like 25 or 30 2 byte halfwords for the card reader and if you wanted to load from tape or disk it was a big load.
The 3890 (used a M/25 for a controller) had the same deal but the code for the 33FD diskette reader was fairly small. The rest of the 360s had hardware ROM loaded microcode. This was either mylar punch cards in the 30, mylar punched tape in the 40 or a larger mylar punched sheet in the 50 and up.
The other machine with a lot of handloaded info was the original IBM ATMs. You had to hand load the two 32 byte encryption keys. The customer was supposed to do that but I never saw one actually do it. I did know some CEs who had both codes memorized for the banks we dealt with. That may have been a security issue ;-)
You could easily hook up a PC to that phone line and pretend you were the host. At that point you could OK any transaction and pump the machine dry (typically about $40k in 10s and 20s)... but that would be wrong.


Greg Fretwell

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