Commodore 128

Read in: IT 🇮🇹   EN 🇺🇸

Il Commodore 128 è un home computer a 8 bit prodotto dalla Commodore Business Machines tra il 1985 e il 1989. E' noto anche come C128 e CBM128 ed è compatibile con il Commodore 64.

E' un computer molto versatile e può funzionare in diverse modalità:

• Commodore 64, ensuring compatibility with the accessories, games and software of the C64;
• Commodore 128 su monitor a 40 colonne, sfruttando la porta Audio/Video e l'uscita RF;
• Commodore 128 on 80-column monitor, by means of the port Rgbi (two monitors can be connected to the Commodore 128 at the same time);
• CP/M (Control Program for Microprocessor) system for Zilog Z80.

Questo è il primo computer ad essere entrato nella mia collezione, perché l'ho conservato da quando ero bambino. In realtà, prima di questo computer, in famiglia già c'era un Commodore 64, ma è stato venduto per acquistare questo Commodore 128. Successivamente, è arrivato un IBM PS/2 model 60.

In addition to the Commodore 128, there are also other accessories in my collection: the floppy disk drive Commodore 1541, the Datassette and the printer Commodore MPS803.

Technical characteristics of the Commodore 128

CPU:

• MOS 8502 2 MHz in 80-column mode or 1 MHz in 40-column mode (or even C64 mode)
• Zilog Z80 4 MHz for the CP/M+ operating system (although, due to hardware limitations, the actual speed is as if it were 2MHz)

ROM, in C128 mode:

• BASIC 7.0: 32 kB
• Screen editor: 4 kB
• I/O and character map: 4 kB
• KERNAL and hexadecimal monitor: 8 kB

ROM, in C64 mode:

• BASIC 2.0: 8 kB
• I/O and character map: 4 kB
• KERNAL and screen editor: 8 kB

RAM: 128 kB divided into 2 banks of 64 kB

Video chip:

• MOS VDC (in 80-column, C128, and CP/M mode)
• MOS VIC-II (in 40-column and C64 mode)

Audio: MOS SID

Keyboard: extended to 92 keys, with numeric keypad

Software included in ROM:

• BASIC 7.0 (C128 mode)
• BASIC 2.0 (C64 mode)

Expansion ports:

• 1 IEC Serial
• 1 User Port
• 1 Expansion port (for Commodore 64 cartridges)
• 1 Audio/Video (CVBS and S-Video composite video, for connection to 40-column monitors)
• 1 RGBI (80-column monitor connection)
• 1 Antenna (RF connection to TV)
• 1 Datassette port (cassette player)
• 2 Joystick Ports

Emulation

E' possibile emulare il Commodore 128 su un comune PC Windows, tramite il VICE. In this way, it is possible to try to start programs and games, as well as program the back computer, in a simple and comfortable way ... without even having the Commodore 128!

Commodore 128 Power Supply

L'alimentatore ha la stessa forma e lo stesso connettore di quello dell'Amiga 500, ma non è compatibile, perché le tensioni di alimentazione sono differenti.

Outputs:

• 5V direct current, 2.5A
• 9V alternating current, 1A

C128 boot screen

In modalità nativa (Commodore 128), la schermata di avvio del computer vintage è verde. Il chip video in fuzione è il MOS VIC-II, lo stesso del Commodore 64, e l'immagine è generata all'uscita Audio/Video oppure Antenna.

To switch to Commodore 64 mode, you can type GO64 on the keyboard, or you can hold down the Commodore key C= all'accensione del computer. In modalità C64, la schermata di avvio è azzurra.

In C64 mode, keyboard keys not actually present in the Commodore 64 do not go. The numeric keypad on the right is not operational and the upper gray keys are not operational either, with the exception of the function keys (F1-F8).

In 80-column mode, selectable with the 40/80 DISPLAY or with special commands in BASIC, the boot screen is with a black background and is generated by the VDC MOS chip, on RGBI output.

Booting the CP/M operating system from the diskette, the processor in operation is now the Z80. The boot screen of the CP/M 3.0 is as follows, having also typed a couple of commands (DIR per leggere l'elenco dei file contenuti nel dischetto e DATE to display the system date).

Papers

1. Commodore 128 introductory guide

2. Commodore 128 system guide

3. Commodore 128 system manual (ITA)

4. Commodore 128 service manual

Date of entry into the collection: it has always been with me!