Altair 8800 behuizing (Computertechniek)

door Mans Veldman , Leidschendam, 31-01-2015, 21:07 (3401 dagen geleden) @ Roland Huisman

Roland,

Ik kan je niet helpen aan een Altair behuizing, wel aan een virtuele Altair (compleet met behuizing).

Ik vond tussen mijn software een vrij uitgebreidde Altair emulator voor 32-bits windows. Volgens mij heb ik hem al sinds windows 98. In iedergeval start hij ook netjes onder Win-7. Hij is vrij uitgebreid inc. ondersteuning voor hardware (flop, serieel, printer, enz.) en software-images voor tape en disk waar onder Basic (Altair en Microsoft) en CPM. Hoe de hardware ondersteuning onder Win-7 is weet ik niet.

Software is public domain en inclusief broncodes. Als je interesse hebt mail mij dan even dan stuur ik het je via WeTransfer toe.

gr. Mans

Hier een stukje uit de helpfile.

Virtual Hardware Specifications
Since the Altair32 Emulator is a Windows-based emulation of the MITS Altair 8800 computer, we can take some poetic license with regards to how capable a machine is emulated . The Altair32 emulates a fully-configured 8800 system with 60k of RAM (4k of the address space is allocated for ROM usage), a paper tape punch and reader, a MITS floppy disk controller with eight Pertec 8" floppy disk drives (including a decidedly unprototypical "large" disk of about 1.1mb), a parallel line printer and a cassette tape interface. The console terminal is emulated by using a common telnet client program, Windows Console services or a real serial terminal.

The general specifications of the Altair32 Emulator is as follows:

CPU
Intel 8080, 2.0MHz (adjustable). 8 software interrupts, one hardware interrupt (unemulated at this time), 64k address space, port-mapped I/O.

Memory
60k RAM and 4k ROM by default. Fully configurable using configuration dialog box. Buss bandwidth limitations/wait-states are not emulated, so memory access speeds are irrelevant within the emulator context.

Serial ports
Two – a MITS 2SIO dual-port card at ports 20Q-23Q (port 1 is the console and port 2 is for the paper tape punch/reader).

Disk
Qty. 8 (controller capacity is 16 drives) Pertec 330k 8" hard-sectored floppy disk drives. Controller sits on I/O ports 10Q-12Q. Disk geometry is 77 tracks of 32 sectors, each sector 137-bytes in size, resulting in an unformatted capacity of 337,664 bytes per disk. A "large disk" format is supported (254 tracks of 32, 137-byte sectors for an unformatted capacity of 1,113,536 bytes). The standard 88-DSK bootrom occupies the uppermost 256-bytes of memory and is accessed by toggling the address 0xff00 and RUNning from there.

Terminal
Terminal services provided through a telnet client resembles any number of ASCII terminals, such as the vintage ADM-3A. Using the Windows Console option results in a color DEC VT100 ASCII terminal. Using the real serial connection enables the user to connect a true terminal to the host computer. BASIC programs stored in standard text files can be pasted directly into the selected client, with the effect the same as if the user typed the program into the emulator by hand.

Line printer
MITS 88-LPC is emulated through a text file capture. Printer is "connected" to the emulator through the MITS-default addresses of 2Q/3Q.

Paper tape device
Paper tapes are emulated through file images accessed by the emulator using the paper tape punch/reader device. The PTP occupies port 2 of the 2SIO serial interface card.

Cassette device
Cassette tapes and paper tapes both used the MITS Absolute Tape Format. The virtual 88ACR interface connects to the emulator through the MITS-assigned ports 6Q/7Q.

Read-only memory
Coupled with the auto-load feature below, binary files can be loaded at emulator startup into any area of memory.

Core programs - tape
Altair BASIC 3.2 (4k), BASIC 4.0 (8k), Extended BASIC 4.0 and Extended BASIC 5.0 (the last version made) through paper tape images. Tapes are loaded using a small bootstrap loader (called the Toggle Bootloader).

Core programs – disk
CP/M 2.2, AltairDOS, Microsoft Disk Extended BASIC, Microsoft BASIC 5.0 through binary disk images.
Other Since CP/M supports large disks, a 1.1mb CP/M hard drive image is indirectly supported.

Using the approximate cost figures from 1976, this system would cost a whopping $11,300.