The PHC-25 was released at the same time as the PHC-10 and the PHC-20, in 1982. Sanyo wanted to offer a perfect line of products for computing initiation. These three models were supposed to be complementary. But despite high hopes, they just were flops and it's not clear if the PHC-10 and PHC-20 were even really sold, as very few were ever found. The PHC-25 was the only model of the line to have been sold with moderate success.
PHC stands for "Personal Home Computer". The PHC-25 was the high-level system of the trio. It offered an extended version of the Sanyo Basic already found in the PHC-20, which itself was an evolution of the Tiny BASIC found in the PHC-10. Editing of the program lines is facilitated by the use of the orange arrow keys found at the top right of the keyboard.
The Sanyo BASIC V1.3 is stored in a 24KB ROM. The computer offers 16KB RAM leaving only 14KB for the user to program in Basic or 8KB if the "SCREEN 2" option is chosen at startup. Indeed at startup a "SCREEN ?" prompt welcome the user. If you enter 1, it means you will just need one screen to be stored in RAM, leaving you almost all the RAM available for Basic programming. If you reply "2" at the SCREEN? prompt, then the computer reserves some RAM for a second virtual screen which could be used by the program.
The PHC-25 is powered by a NEC D780C microprocessor running at 4 MHz, which is compatible with the Zilog Z80A. The chip used for the video is the famous Motorola MC-6847 Video Display Generator, well known for its omnipresent green colored background, and also used in many systems of that time including the TRS-80 Color Computer, Dragon 32/64, Laser 200, TRS-80 MC-10, NEC PC-6000 series, Philips VG5000> (used the Thomson EF9345 compatible chip) or the APF Imagination Machine, among others. Inside the plastic case, everything is arranged on two motherboards connected to each other through a ribbon cable.
This MC-6847 chip offers different text and graphic modes, each with a subset of colors available:
- Mode 1: 16x32 (text) in 2 colors
- Mode 2: 16x32 (text) in 4 colors and 64x48 (semi graphic) in 8 colors
- Mode 3: 16x16 (text) in 8 colors and 128x192 (graphic) in 8 colors
- Mode 4: 16x32 (text) in 2 colors and 256x192 (high resolution graphics) in 2 colors
The set of BASIC commands are:
RUN, NEW, LIST, CSAVE, CLOAD, CLOAD?, CLEAR, CONT, EXEC, LLIST, DATA, DEFFN, DIM, END, FOR～NEXT, GOSUB～RETURN, GOTO, IF～THEN, INPUT, INPUT#, KEY, LET, LPRINT, LCOPY, ON～GOSUB, ON～GOTO, OUT, POKE, PRINT, PRINT#, READ, REM, RESTORE, RETURN, STOP, SOUND, PLAY, CTON, CTOFF, ABS, COS, EXP, INT, LOG, RND, SGN, SIN, SQR, TAN, CSRLIN, POS, LPOS, PEEK, SPC, TAB, TIME, USR, POINT, FRE, CHR$, LEFT$, MID$, RIGHT$, ASC, LEN, VAL, INKEY$, STR$, STICK, STRIG, INP, SCREEN, COLOR, CONSOLE, CLS, LOCATE, PSET, PRESET, LINE, PAINT, SLOAD, SSAVE.
This is a very complete BASIC which is in fact compatible with the NEC PC-6001 one. Thus, the PHC-25 if virtually "BASIC" compatible with the 6001, but some instructions and features need to be modified before running the program. Curiously, it is not the only similarity between these two computers. The colors of the plastic case and keys are almost the same: beige and cream with grey and orange keys ! Alongside the BASIC compatibility, the electronic components are the same. Chances are it must have been intentional.
Strangely enough, the computer looks like it was not entirely finished or if the designers lacked some space to implement all the features. Thus, you need to buy the famous PSG-01 expansion box if you want to have sound capabilities on your PHC-25. Crazy if you think that even the cheap PHC-10 had a internal buzzer to play with. Anyway, connect the PSG-01 box and you've got a real 3-voices synthesizer to play with. You even get two DB9 "Atari compatible" connectors to plug your favorite joysticks in order to play...
Well, that is the main problem. The PHC-25 has maybe the worst ever choice of games available in the world ! Most of them are poor BASIC games, only INVASION (clone of SPACE INVADERS) being a real machine code game worth being played.
Today, the Sanyo PHC-25 seems to be a rare machine. Very few were sold, and most of them were apparently distributed in France, hence most of the games found online are in french.