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9
votes
6answers
1k views

What did order processing on a teletype look like?

The earliest business data processing systems were based on batch processing of punchcards. Prepare cards off-line, feed a batch of them through the computer. (Why does one so often hear of payroll, ...
3
votes
1answer
170 views

Porting of software from the m68k family architecture to the DEC VAX

I am looking for impressions, memoirs, articles, guidelines - everything that is possible about the unusual direction of software migration. I am interested in non-Unix related code, and preferably ...
17
votes
1answer
970 views

How did the Nova 1200 divide so quickly?

According to https://en.wikipedia.org/wiki/Data_General_Nova The Nova 1200 executed core memory access instructions (LDA and STA) in 2.55 microseconds (μs). Use of read-only memory saved 0.4 μs. ...
17
votes
1answer
1k views

How did SABRE work interactively without screens?

The SABRE airline reservation system went online in 1964, astonishing the world by being among other things the first large-scale interactive computing system. Once the IBM 3270 video terminals were ...
7
votes
2answers
193 views

Why was the VT05 resolution 72×20?

According to https://en.wikipedia.org/wiki/VT05 the VT05 presented the user with an upper-case only ASCII character display of 20 rows by 72 columns. At first glance this seems a reasonably natural ...
14
votes
5answers
2k views

Advantage of RS-232 over 20mA current loop

According to https://en.wikipedia.org/wiki/VT52 Like other early DEC terminals, the VT50 series were equipped with both an RS-232 port as well as a 20mA current loop, an older serial standard used ...
5
votes
1answer
185 views

What information was present in line printer printout cover/trailer?

Nowadays, in corporate offices where there are typically several office printers per floor, sending a file to a printer does not result in any additional pages identifying the print job, at least by ...
9
votes
4answers
571 views

Delay loop in BASIC

Yesterday I was looking for a way to implement a delay loop on the C64. I came across this page: https://www.c64-wiki.com/wiki/TIME At the bottom of the page there is a code fragment that waits for a ...
3
votes
0answers
91 views

Converting AC'97 to a standard that can be used by my Soundblaster

I currently enjoy using a Windows 98 PC I built using parts I got either for free or very cheap. One of those parts is a sligthtly modern case - the cheapest one I could find that has a 5.25" and ...
2
votes
1answer
127 views

Modern heat sinks for Commodore C64/C128

The VIC-II and SID chips in the C64/128 are prone to over-heating and are rather expensive to replace nowadays. Some other ICs in these machines may have the same issue. An unmodified machine includes ...
5
votes
3answers
920 views

How can I read COM port addresses from BIOS in QuickBasic 4.5?

I have been using the following code to get comm port addresses from BIOS in QuickBasic 4.5: PRINT "Hex addresses for ports 0 to 3 from BIOS." DEF SEG = 0 FOR x = 0 TO 3 z = &H400 + ...
5
votes
3answers
280 views

Modern (cooler) replacements for vintage static RAM chips

The device I'm using (a SYM-1, probably c. 1979) has a stack of L2114-UCE 1024x4 static RAM chips ("2114 static, TTL in/out 1024x4 N-MOS RAM", the -UCE means "450ns access time, 315mW ...
4
votes
2answers
437 views

How much memory does this SYM-1 have?

I have a SYM-1 with the following memory configuration: How much memory is that? Those all appear to be L2114UCE chips, which are described as "Static 1024x4 NMOS RAM", but I'm not sure how ...
0
votes
2answers
214 views

CPU slaves on a PCI card to retrofit single processor to multiple processors. Any ideas how? [closed]

My desktop computer is no longer manufactured and no longer supported since more than 18 years ago. It was a very expensive top of the line business computer back in the day. I like it and wish to ...
7
votes
1answer
1k views

I can't read DS 1MB floppy disks

Using an USB external floppy drive, I've been able to use my Mac to back up files from a big box of 3.5 inch floppies (800K, HD 1.4MB). But I cannot even read my DS 1MB floppies using either the ...
4
votes
1answer
530 views

Sym-1: What is the “f” register?

Running SUPERMON on a Synertek SYM-1, the R (REG) command cycles through a number of registers. Most are self explanatory: p is the program counter (pc) s is the stack pointer a, x, and y are obvious ...
11
votes
2answers
2k views

Intel 386 multiply bug

Some early models of Intel 80386 processors had a bug with 32-bit integer multiplication. Those which were found to have the bug were marked "16-bit S/W ONLY" (not sure what S/W is supposed ...
22
votes
1answer
2k views

Where are the sources of the original curses library?

The curses library is a terminal control library for Unix-like systems used in text based user interface applications. It has been used in many games in the past. It was developed by Ken Arnold and ...
32
votes
6answers
8k views

Why is EEPROM called ROM if it can be written to?

Is there a historical reason? Since it is rewritable it isn't read only by definition, so why call it so?
12
votes
3answers
1k views

What 8086 instructions accept REP?

I tried this code in my assembler, set to 16 bit mode: bits 16 rep mov ds, ax Surprisingly, no error was thrown. Is this even valid? Wasn't rep only supposed to work with string instructions? Is it ...
1
vote
1answer
311 views

What to do with stone age x86 computers? [closed]

Not sure if retro is proper place... I have two old notebooks with x86 processors in the 100s range of MHz. While nostalgics might appreciate them, I'm wondering if there is any proper point in ...
10
votes
1answer
701 views

PET as a terminal

While reading about the SuperPET I just recalled another PET modification. My uni had an 11/780 that I learned FORTRAN on. It used modified PETs as input terminals. This took the form of a modified ...
2
votes
1answer
201 views

What's with the TX-0 punchtape instructions?

The TX-0 has a class of instructions very similar to the PDP-style microprogrammed, operation instructions. Fill the opcode field with all ones, and then select which microoperations you want to ...
6
votes
1answer
145 views

Chaining IRQ's with BASIC & Kernal routines turned off

Having disabled BASIC and Kernal routines I set up an IRQ to run the following code when the raster line reaches 200: .irq1 inc 53280 // change border colour // lda #$ff // clear the ...
4
votes
1answer
222 views

PC 90s 2D Platformer Puzzler Indie Exit Levels With Robot

Platform(s): PC (Used to play on Windows 95/98) Genre: 2D Platformer, Puzzler, Indie, Overcome some square obstacles, Exit to door or portal next level (100 levels approx if not a bit less or more) ...
7
votes
2answers
425 views

Reverse engineering an RS-422 protocol with access to only one device?

I have a console, but not the main computer it's designed to connect to. My goal is to interface this with a (Linux) PC, and hopefully more than just the keyboard. I have never tried something like ...
4
votes
1answer
121 views

Macintosh II ROM Replacement

I'd like to upgrade my Macintosh II to FDHD, I have a SWIM chip (to replace the WIM chip), but don't know how to burn the ROMS. The upgrade process I'm trying to do is described in the book: "...
4
votes
1answer
235 views

Identifying and recovering programs from tapes

A couple of days ago, I was given some old tapes with programs written on them. However, I am having some trouble with them. I do not know what computer they were programed for. After recognising the ...
4
votes
3answers
222 views

Running WarpCopy64 on an emulator

I'm interested in IP networking capabilities of the Commodore 64. I learned there is a tool called WarpCopy64 that can be used to run a simple file server on the Commodore. The server can be accessed ...
2
votes
0answers
121 views

Was There a Release of WMI for Windows NT 4.0 Running on DEC Alpha?

Windows Management Instrumentation (WMI) was made available as a separate download for Windows NT 4.0 SP4 and above. I know that WMI installs and works great on Intel IA32 (x86) flavors of NT4, ...
23
votes
12answers
7k views

Was memory corruption a common problem in large programs written in assembly language?

Memory corruption bugs have always been a common problem in large C programs and projects. It was a problem in 4.3BSD back then, and it's still a problem today. No matter how carefully the program is ...
6
votes
1answer
266 views

Can the 80-column display really be improved on a C128 and 1902A monitor?

The March 1988 issue of RUN contains the following tip from a reader on page 20: Attention: C-128/1902A Owners! If you use a Commodore 1902A video monitor with your C-128, here's a way to get a ...
2
votes
4answers
718 views

Are there some non-OOP programming languages that does not allow you to make a variable private? [closed]

In the non-OOP programming languages that I know of, you can't make a variable private (i.e. there is no private keyword), but there are some tricks that you can use to effectively make a variable ...
6
votes
3answers
329 views

Is it still possible to access a BBS via dial up internet on the C64 (or other retro computers)

I was wondering if it is still possible to access any online BBS using dial up and an 80's era computer. I'm aware that some dial up internet providers still exist (eg Nippy Internet in the UK), but ...
4
votes
0answers
105 views

Macromedia Flash Desktop API / EXE bundler

Sorry if this is too recent, but back when I was first getting into programming in ~2002-2004, there was some Flash/SWF-to-EXE tool that provided ActionScript bindings to Windows desktop APIs. Does ...
6
votes
2answers
263 views

Documents about timesharing systems, access and resource control and its financials

I delved a bit into the origins of (commercial) timesharing and it seems there have been very interesting computing hardware and software (architectures) which have become relatively unknown but may ...
6
votes
4answers
1k views

Efficient way to JMP or JSR to an address stored somewhere else?

I'd like to JSR or JMP (preferably JMP as it's 3 cycles cheaper) to an address stored somewhere else in memory, the address of which is itself indexed. I came up with the following self-modifying code ...
4
votes
1answer
183 views

Use a USB mouse for DOS games

I have a Thinkpad T41 on which I installed Windows 98 SE. I installed an old DOS game, and was wondering if I could get a USB mouse to work with it ? (the PC doesn't have a PS/2 port) At the moment, ...
3
votes
2answers
318 views

What high nibble values can you get when you read the 4 bit color memory on a C64/C128?

The C64 and the C128 have a memory for storing the color values of a character. The size of this memory is 1k x 4bit (2k x 4bit for the C128 which can do a double buffering), thus reading the value at ...
30
votes
13answers
6k views

In what language(s) is the return value set by assigning to the function’s name?

In this Stack Overflow question the original code made the mistake of using the function name as a variable, and assigned the return value to it. A commenter mentioned that he once used a language ...
1
vote
1answer
260 views

Why did IBM decide to use 8 bits for EBCDIC?

Why did IBM decide to use 8 bits for EBCDIC? 7 bits per character seems reasonable, since 2^7 = 128 symbols which is enough for all English letters and special symbols.
36
votes
3answers
6k views

How can I visit HTTPS websites in old web browsers?

I'm having trouble accessing HTTPS websites using Netscape Communicator 4.8. This is the error message I get: Is there a way I can configure some sort of proxy that will allow me to access HTTPS ...
7
votes
2answers
702 views

What was the first microprocessor to overlap loads with ALU ops?

Modern out of order CPUs can do all sorts of things in parallel, having not only multiple functional units, but a lot of logic to check at runtime exactly which instructions really depend on others, ...
2
votes
2answers
304 views

What was the DRAM refresh interval on early microcomputers?

Dynamic RAM is denser than static RAM, but needs to be refreshed every few milliseconds to avoid losing data. How many milliseconds, exactly? If the answer has changed over time, then I'm interested ...
8
votes
1answer
388 views

What is language use for level name in level 3 and 5 of Strider arcade game? [closed]

Arcade strider game show level name use different language follow Strider Hiryu (飛竜)'s adventure. But I not recognize languages for level 3 and level 5. Can see titles in this video, Arcade Longplay [...
3
votes
0answers
107 views

Task manager for Mac OS 8/9

Does there exist either an embedded task manager, or a third party task manager for for Mac OS 8/9? So I can: View currently running tasks Kill processes View system load
0
votes
1answer
136 views

Defining a C function with given address in cc65

I have a function that should be callable with the following syntax: void __fastcall__ initSIDplayer1(uint8_t a); The __fastcall__ modifier here means that the argument is passed in the Accu instead ...
7
votes
4answers
2k views

What are people using old (and expensive) Amigas for today? [closed]

I recently sold a defective Amiga 1000 on Ebay for over $300. I'm going to list my old Amiga 1200 and expect to get over $1000 for it since its working and "souped up". This made me wonder: ...
0
votes
3answers
309 views

How was “Super Mario Bros” made with Assembly if the DASM compiler came out in 1987?

Would somebody care to explain how "Super Mario Bros." was released in 1985. But the DASM Assembler came out in 1987? The 6502 Assembly language was introduced in 1975. How would you compile/...
4
votes
2answers
400 views

The use of segments in non-relocating assemblers

I've been looking at a bunch of different 6502 assemblers recently (dasm, ca65, xa, kickass), and many of them have support for multiple code segments. Some of these assemblers can generate ...

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