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2
votes
3answers
47 views

Why did post-8008 CPUs not keep the on-chip stack idea?

According to http://www.righto.com/2016/12/die-photos-and-analysis-of_24.html The 8008's seven registers are in the upper right. In the lower right is the address stack, which consists of eight 14-...
5
votes
1answer
180 views
+50

What are the needed jumper settings for a 68060 accelerator for an Amiga 3000T?

I'm trying to install a 68060 accelerator on an Amiga 3000T, but I cannot figure out the correct jumper settings. The information I've found online is: J100 CLK90 Delay jumper. This Jumper has three ...
71
votes
4answers
18k views

Why does part of the Windows 98 Setup program look older than the rest?

When installing Windows 98, the part of the setup process where you enter things like product details looks... different. The scrollbars, buttons, title bar and such look more like they belong in ...
1
vote
1answer
46 views

Are all 64k x 4-bit ICs interchangeable for Amstrad-era ZX Spectrum 128k +2/+3?

There were 4 64k x 4-bit Integrated Circuit chips in the Amstrad-era Sinclair ZX Spectrum +2 and +3 models. These are known as the +2A, +2B (both +2 "black"), +3 and +3B (also both black cases). I ...
6
votes
4answers
3k views

How can a Z80/8080/6502 use VGA?

I've come across a couple of projects that manage to get VGA working with the Z80 and similar CPUs: Veronica (6502 CPU, VGA signal generation by AVR) ZC160 (Z80 CPU, VGA signal generation by GAL) c-...
3
votes
3answers
630 views

What are D64, T64, D71 and D81 files?

The docs for Ultimate-II+ expansion cartridge for the Commodore 64 state: It is able to read D64 files, as well as D71 and D81 files (no partitions), T64 files. So what are D64, T64, D71 and D81 ...
0
votes
0answers
80 views

Problem accessing Internet from old devices (HTTPS, SSL, certificates, compatible services,…)

I am trying to find information and resources about connecting 18-12 years old devices to Internet, and more specifically PDAs and phones (*). The purpose is recreational and curiosity, so no the ...
1
vote
1answer
139 views

What is this socket for in 386 notebook motherboard

What is this socket for on 386 motherboard? I have no manual, no documentation and no resources readily available for this machine (Commodore C386SX-LT).
12
votes
4answers
3k views

Which are the earliest real-time text editors?

A real-time text editor is a program which facilitates editing text. In the process, the text is displayed on a screen, and the displayed text is updated after each key press. A commonly cited ...
46
votes
13answers
16k views

How was it back then in 1984, when the Apple II had color, and the new Macintosh didn't?

I imagine it being a huge downgrade for some, not to have color on the Macintosh. Macintosh games were black and white in the beginning, while Apple II had color. I'm especially interested in ...
5
votes
1answer
336 views
+50

Modern Alternative to Malvino's Digital Computer Electronics

For those who want to study retro computing in depth, starting by understanding 74xxx logic and CPU design is (IMHO), one of the best paths there is. Malvino's "Digital Computer Electronics" (DCE), ...
34
votes
7answers
5k views

What languages are better fit for generating efficient code for 8-bit CPU's than C?

I found Why do C to Z80 compilers produce poor code? very interesting as it pointed out that C (which was designed to be an abstraction of a CPU for porting Unix) was not a very easy language to ...
12
votes
2answers
3k views

How do C64 cartridges swap running programs without losing state and context?

I recently picked up a 1541 Ultimate II+ for my Commodore 64 and have been amazed at how this device seemingly can do every flash memory and other enhancement feature for the machine, short of CPU ...
98
votes
16answers
22k views

Does “Disk Operating System” imply that there was a “non-disk” Operating System?

In the 1980's at primary school we saw MS DOS and DR DOS competing before Windows 3.1 and subsequent releases took over that space. At home we had Apple II's which booted up to a BASIC prompt. On ...
-1
votes
0answers
103 views

Why fight the protocol wars? [closed]

There is a well known war in computer science that involves a lot of its domains: The Protocol War (https://en.wikipedia.org/wiki/Protocol_Wars). I would like to know, what was the reason companies ...
4
votes
5answers
492 views

Z88DK ZX Spectrum “%f” printf not working

I'm attempting to compile a program in C for the ZX Spectrum using Z88DK. However, I'm facing an issue when trying to use printf to print out the value of a float. The code I'm trying to compile: #...
3
votes
1answer
45 views

Converting Apple II ProDOS blocks to DOS tracks and sectors

The 8-bit Apple II had two disk operating systems with different disk access semantics. DOS used tracks and sectors. A sector is 256 bytes. ProDOS used blocks. A block is 512 bytes. But mapping ...
7
votes
2answers
730 views

How can I programmatically determine whether an Apple II .dsk disk image is a DOS .do image or a ProDOS .po image?

I'm interested in working with the most common Apple II disk image file format, .dsk. (I only programmed these machines briefly in Basic around 1979-81 and have not been in the emulator scene, so I'm ...
1
vote
4answers
373 views

Is this a computer screen in 1956, and if so, what is it displaying?

The photo below shows what may be a CRT for the TX-0 (transistorized experimental computer) in 1956, referring to what may be a CRT on the left side, not to the CRT on the right side . If that is a ...
0
votes
2answers
43 views

Reading 360k floppy disk in 1.2M drive

I formatted several 5.25" diskettes with 360k and 1.2M on the Windows XP PC using 1.2M (HD) drive. I am using the same drive to read data from 360k diskette back using custom driver. The controller ...
8
votes
5answers
2k views

Connect Ethernet via Parallel or Serial in old laptop

Is it possible to connect an old 386 machine to network (ethernet)? It has only parallel and serial ports. I'm not expecting much, just planning to use it as a remote terminal. The machine in question ...
1
vote
0answers
25 views

What is the layout of the directory track on a TRS-80 Model I/Model III disk?

I've decided to add support for some more classic Z80 computers I used to use to my Ghidra modules, and the first Z80 systems I used were the TRS-80 model I and model III. I've found documentation ...
0
votes
2answers
185 views

What’s the last x86 CPU that didn’t place a limit on the size of a single instruction?

Although useless, it’s widely known the first Intel and derivative CPUs like the Z80 didn’t set a limit on the instruction size. This means that it was possible to fill the whole RAM/ROM with a single ...
2
votes
1answer
161 views

Is this real Commodore C386SX-LT

Is the model shown on pictures an authentic Commodore C386SX-LT? Why does it look different to other photos on the Internet (some additional grey keys? above keyboard): http://www.spacereh.de/hc/com/...
1
vote
0answers
100 views

Did the Mega Drive and/or Arcade version of the song “Afterburner” use FM synthesis or samples?

Does anyone know if the Mega Drive or Arcade version of Afterburner use FM synthesis or sound samples for orchestra hit in its song "Afterburner". I find oscilloscope views of each version but I'm not ...
11
votes
3answers
2k views

Decoding Logic and Memory Systems for 8-bit computer - 64K address space

I am creating a minimal Z80 computer with serial output on a breadboard. I have kind of moved up from the last question, where I was executing instructions on Z80 using specific connection of ...
6
votes
4answers
441 views

Are there standard DIN pinouts for cassette and video ports on early Japanese 8-bit computers?

I have several different Japanese 8-bit computers, and they use similar DIN connectors for video and cassette I/O: Composite video: 180° 5-pin DIN: Fujitsu FM-7, NEC PC-8001mkII Color TTL (digital) ...
12
votes
2answers
1k views

Should I use the internal or external drive for loading Amiga 500 games?

I have a working (I think) Amiga 500 system with an internal DF0 drive and an external DF1 drive. The Amiga 500 powers up with Workbench v1.3. Can anyone tell me how to access a game disc (Marble ...
27
votes
2answers
3k views

Apple II: Applesoft BASIC memory management

I am trying to write an Applesoft / floating point BASIC program using high resolution graphics and some assembly language code. My BASIC program is quite large, and after running the program for a ...
2
votes
2answers
115 views

HDD data recovery advice

I found my assumed long lost “win98” toshiba protege laptop in our wet and moldy storage container. Was there for years, through cold-humid variances. The files on his computer are extremely ...
3
votes
1answer
229 views

What was the history of Nanodata Corporation?

Nanodata was a Buffalo, New York company that was formed in 1971 and seems to have sold its first products in 1973. They filed for bankruptcy in 1982, though they may have carried on business for a ...
4
votes
2answers
284 views

Sharp Super Scientific EL-9000 English Manual

I have a Sharp Super Scientific EL-9000 calculator (that used to be my mom's back in the day) which came with a Korean manual. I am a Korean American, and I can't understand the manual well. Does ...
3
votes
1answer
62 views

Do TRS-80 Model I and Model III load and execute /CMD files using specific memory addresses?

/CMD files on the various TRS-80 Model I and III OSes are machine code command files. They seem to have some internal format but not really a file header. They often start with 01 02 and then a 16-...
3
votes
8answers
749 views

Did people back then build powerful computers out of multiple smaller machines?

Did people back then build powerful computers out of multiple smaller machines ? Build powerful computers out of >1 smaller machines Time range - approximately 76-82 (I accept exceptions, ...
3
votes
2answers
83 views

Is there a “most correct” name for the disk format / filesystem used by Amstrads and Spectrum +3's?

The native floppy disk format/layout or "filesystem" used by Amstrad microcomputers such as the CPC and PCW range and by the Sinclair Spectrum +3 are versions of one that came from CP/M. In Amstrad ...
5
votes
2answers
145 views

How to get out of Apple IIe mode on Macintosh Color Classic?

I just picked-up a Macintosh Color Classic with an Apple IIe card. I've never used one of these before but was able to get it to enter into Apple IIe mode. However, I cannot seem to figure out how to ...
12
votes
1answer
2k views

How can Windows 98 shut down in less than 5 seconds?

I have used Windows 98, and observed that its shutdown is very fast. How is that?
1
vote
1answer
140 views

Connecting analog pedal from sewing machine to computer audio jack [closed]

I got a control pedal from an old sewing machine that connects to a 3.5mm jack. It fits in the audio/microphone jack of my laptop. Is there any way that I could detect from the laptop this pedal ...
5
votes
2answers
547 views

How could a 16-sector PROM Apple II access a 13-sector disk?

When the Disk ][ first came out for the Apple II, the PROMs on the interface card only knew how to work with a 13-sector format. Around 1980, the Disk ][ was updated with 16-sector PROMs either for ...
2
votes
1answer
109 views

What is the file that VICE refers to as dos1541?

VICE needs a file called dos1541 if you want hardware emulation of the 1541 disk drive. What does that file contain, exactly? The 1541 seems to have two ROMs: a DOS and a KERNAL. But if I take the ...
29
votes
4answers
1k views

Absolute maximum number of nibbles on an Apple II floppy disk track?

The Apple 2's disk drive controller and 5¼" floppy disks have the following metrics: The disks is spun at (roughly) 300 RPM (Revolutions per Minute), which means it takes = 1000 ms/sec / (300 RPM / ...
29
votes
5answers
8k views

Why did the Apple IIe make a hideous noise if you inserted the disk upside down?

When I began high school in 1987 all the computers in the lab were Apple IIe desktop computers. A question has haunted me since then: if you inserted a floppy disk "upside down" the Apple IIe would ...
9
votes
1answer
90 views

In TRS-80 parlance when talking about disks, what are “granules” and “lumps”?

In my reading to try to learn about the disk layout, directory, and boot process of TRS-80 Model I and Model III, I see some unusual words come up again and again. Along with the common terms "track" ...
4
votes
1answer
105 views

Why is my Macintosh LC 475 playing chimes of death when I install more ram?

I bought an LC 475 for parts and repair on ebay. When it arrived it seemed to work okay but the video was all stripey. After some diagnosing I spotted a rotten trace near the the VRAM simms. I ...
3
votes
1answer
70 views

What is the process for TRS-80 Model I & III to boot from disk?

I can find enough mentions of bootable disks for TRS-80 Model I and Model III to be confident that they could boot from disk, but so far I'm failing to find much info on how that worked. In ...
2
votes
1answer
84 views

How was the second bank of Apple IIc ROM accessed?

The original Apple IIc had a 27128 16 KB ROM mapped into the $C100-$FFFF range (the $C000 page was decoded for I/O). According to the Apple IIc Technical Reference Manual the ROMEN1* and ROMEN2* ...
5
votes
1answer
173 views

What is the format of the static libraries shipping with legacy Microsoft C for DOS?

I have installed Microsoft C 5.10 on DOS 6.22. It created a 'LIB' directory with static libraries to link against. Now I need to extract the symbols and the code for the functions from them, but can't ...
1
vote
1answer
72 views

Are there open source Java libraries for reading DSK and EDSK disk image files as used by Amstrad and Spectrum +3 emulators?

I've been working on some modules for the Ghidra reverse engineering tool. Ghidra is written in Java, which I'd always avoided when I was more actively programming so this is an opportunity to learn ...
4
votes
3answers
389 views

Is there any tool to convert .DSK to mp3 file?

I was looking into the Apple II disk server (See below for background information) and curious if there is a tool that can actually convert .DSK image to .MP3 file, as the underlying c2t only supports ...
4
votes
3answers
120 views

The 8086 has AAM (ASCII Adjust after Multiply), why not the same for packed BCD?

I'm just curious why the 8086 seems to be lacking in an adjust opcode for fixing up packed BCD multiplication. It seems like it would be a useful thing, and packed BCD seems to be more common to begin ...

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