Japanese

MZ-40K

Finally, I carried out my dearest wish. It is only the 'body', I could get a beautiful machine. MZ-40K is an ancestor of MZ series that exists before MZ-80K, SM-B-80T/TE was designed for Z80's training in a part of semiconductor business, but MZ-40K sold as toy to catering to microcomputer boom. I talk detail later how unusable it is...
My first contuct with MZ-40K is at the shop of MTK electronics located by 10 minutes waliking from Hanshin Amagasaki station in 1980. This shop would change to Fujitsu specialty, but it is SHARP speciality at that time. At second floor there was computer school with 4 or 5 MZ-80C, the shop was complete. At same floor it was seld Apple][. There is a showcase or low bookstand at this shop's first floor, MZ-40K set with musical face keyboard, MZ-40K2. I forget its power was on. But I found that board computer is good at plaing music when I saw that special keyboard. The color's PC and the sound's MZ was succeed from first genetation...(however, it is untill release of PC-6001...)
The next time is 2 years later, when I paticipated training by the certain crammer school in Yoyogi international youth center, I found MZ-40K at computer corner in science museum at Kudan when went sightseeing by bus. I could see the LED and keyboard because it was put into steel case for display, but I found that is MZ-40K from musical face keyboard by it. There was discription by side, it said "if you input all steps accrately, microcomputer become a organ," and discripted about 20 steps oparations. I input thiers gladly and reproduce function of organ completely, but from MZ-40K's manual, I might take in... 15 years later I went to science museum, the computer coner had moved and changed display. MZ-40K had scraped when remodel...

I forget when I did, I happened to remember about MZ-40K and want it. But the chance don't come easily. Others got MZ that remain at toy shop in somewhere accidentaly, because I say too late that I want it. When I come to think of it, it is no wonder, there is no owner around me(I also saw mostly in magazine).
But, the situation is changed by Yahoo! Auction. It still same that it is super-rare-item, but there is unusual exhibitor. I bid with an eye to it, but it is far from easy.
First, it was exhibited for 50000 yen with box and manual. Exhibitor came accros my museum site after exhibition, then send email for me about exhibition. I wont rather stop exhibition than tell me... Then, I have bold bid but was expensive, but I gave up because the price is over 100000 yen.
Next, it was exhibited for 1000 yen with box, manual and MZ-40K2 as musical face keyboad. But it is also rise in price, I would try to sniping(snatch with high price at the last moment), the last bidder seems to bid over 100000 yen, I gave up too.
Next, it was exhibited for 15000 yen without construct. At auction, incomfirmable working when exhibit, as constructless kit, is a fact of uneasiness. Because of it, the bidding pace is slow, I bidded but its price was over 70000 yen, I think it will be over 100000 yen, I also gave up.
The 4th times, it was exhibited for 20000 yen with box and manual. But the exhibitor said, "This is not full working." Because of it, the bidder appear a little, my tender was accepted with 38500 yen. Working part' picture was carried, I think it will be repairable because semiconductor part's brakedown, as CPU, are rarely. Others don't have affection after all...
Now, I'll take details about MZ-40K to you. It is just a one-board microcomputer, but it exists some difference from any other microcomputer board, TK-80 or SM-B-80TE. It have acril cover at surface and stay at both side. The case is just simple, but it seems to feel like other one-board and it is contrived to use safety. But, the target user who are needed contrive to use safety are difference from user have TK-80...
This both side stays don't fix by screw, the CPU board is just inlaid. There are grooves for acril cover and board, and they are inlaid into grooves to fix. There is one more groove for "how-to-use card".
MZ's logo is same as later's one. It seems to differ with '4'. We don't need to mind because SHARP changed logo type 'S','5','6','8' and etc.
And, it doesn't exist "it" MZ series always have. It is the Algo ship. Algo constellation mark, is MZ's symbol, does not draw. It is showing that Algo mark was chosen at being on sale MZ-80K.
Mini plug above the board is from power supply, this is AC11V. Its form is same as ordinary AC adopter, but this does not rectify. Rectification process on board. Because, MZ-40K use trigger to provide clock function. To use clock, it need to adjust for AC's cycle. (In Japan, AC's cycle is wrong between east and west. East Japan is 50Hz, west is 60Hz.)
VR by AC-INPUT JUCK is sound's volume, it same as radio's volume with power switch. Of course, this switch is used to power on and off.
@Keyboad's character is written in white,blue or red on black ground. It seems to feel similar to MZ-80K in after year. Keys have minimum needing funtion, but most keys are made musical scales.
This is the CPU. I have a thing that I'll make clear. I think there are many irresponsibl discription about MZ-40K's CPU in the World(mostly in Japan). Users are few and most fliers were lost, then it is difficult to get accurate information and it's natural to make mistakes, but...
For a period, succesive MZs were appeared serially in Oh!MZ(Softbank's magazine)'s table of contents. In MZ-40K's discription, the CPU's product number is "X0036PAZZ"(appear under SHARP's logo in left picture), this is a only reference number by SHARP, is not a product number.
There is the site MZ saiko jigyodan(MZ revival organization) by really MZ fan, by the keyword page, MZ-40K's CPU is Z80. MZ-40K is 4bit machine, of course, it is  wrong. There are discripted in somwhere's page that is Intel's 4004, perhaps, he may know only i4004 in 4bit CPU.
Now, truth is here. Manual has accurate informations. CPU is MB8843, one-chip type microcomputer, by Fujitsu. MB8843 has ROM(1KB), RAM(64words*4bit) and 37 I/O ports. It is in 42pin DIP package, but most terminal can be assigned for I/O, it seems to some powerful CPU in embedded computers. I don't know it is directry or not, descendant of MB8843 were good sale for mouse. It is difficult to comfirm because CPU is mounted in rotated 180 degree, it is really Fujitsu's package design.
At the picture's bottom, there is "denwa". This is the jumper-line for telephone charge account, it is one of built-in programs, setting for charge per time. It can be set up to 15 yen in anticipation of a rise in price, but nobody will be able to have a forecast that is a fall in price. And it exists under decimal point...
This is RAM. It is MB8101 by Fujitsu. I don't know the details because I don't have a catalog, manual saids, they have 512words*4bits in the tolal two chips.
The left is a manual. It is very thin. The mostly contents is discription of buliding, but how to use is less. I surprised that CPU instruction table is none. In details, MZ-40K have a function of execute included programs in CPU, but it doesn't open for user. It may possibly be exist methods, I can't find it. Monitor program was just like as any other one-board microcomputer's one, it may possibly be only looking, it may work in difference from we look.
The right is "how-to-use card". It is miserable that all function is discriptable in the card in both sides. It taked over the card was annexed to software especialy DISK BASIC in after that.
This is a box. It have a background picture of enlarged photo of silicon routing, we reminded of semiconductor curcuit, it is a common design in after MZ series. What touching catch copies on cover. "Fly out to the World of microcomputer!"(Tobidase! Maikon no sekai e.)... I think a small World that could be experienced. "With enjoying, you can master about microcomputer."(Tahoshiminagara maikon ni tuyokunaru)... it seems to just fun, but I don't think it's a useful to study microcomputer. And it wrrite "An Introduction to The Study of Micro-Computer" at the side of box. It's only use for study...
MZ-40K will not works full when it exhibited for auction, after it came to my hand, I tried to work it and found sound and clock not work. About sound, it worked when exhibited, I checked the parts around of amplifier, then I found the land exfoliation that electrolysis capacitor connects from amplifier circuit to speaker. I connected strap line again along circuit pattern then it output sounds as before.
I thought clock function's repair was worry, I checked circuit diagram at first. Set time was displaied after setting time but second dot didn't turn on and off, then I watch trigger input for clock, but there were 3 inputs like clock. Setting time needs a number met frequency of power line, I thought doubtful about line from AC adoptor, it seems to transister 2SC373 convert high voltage to TTL level. No trigger means this transistor is brakedown, or it may be trouble come from the snapping of a print pattern, bad solder or breakdown of input buffer of CPU. If it was last one, I cannot repair. Then, I prepared a circuit tester, and I would investigate carefully where signal reach...to my surprise, the transistor was installed in reverse porarity (^_^;). Reverse connection might break this transister, but I reinstall it with a ray of hope, then I succeed to repair clock function easily...
There were evrything trouble, but it become a  full working set. If they stop bidding by reason of not full working, I thanksed to exhibitor.

Spec

There is no offical spec table. It may be not a age of compare specs...


Background

MZ series was not made by computer division of SHARP. Far from it, nobody knows personal computer could pay, then there was not a division of personal computer. Like as he episode of TK-80's birth of NEC is from working out a scheme of increase of needs of second source's 8080 by semiconductor division, MZ series were born in parts division that isn't related to computer directry (HAYAC series, is office computer, shuld already exist. Perhaps at the industry equipment division...).

In parts division, 4-bit class microcomputer was used for an electronic oven,etc. Just at that moment, it was in full swing of microcomputer boom by TK-80. It seems that SHARP decided to sell microcomputer kit by our technology with catering to the boom. By the consumer electrical appliance trade's common sence, "get the second position". They get other company to create the boom, and examine the problem, then sell products of expected by consumer, make more money than all of other company at last. It was the times when that thinking was still allowed.
According to the concept of MZ-40K, I think that the strategy of beating the existing products was the following:

This one-boarded microcomputer, was named "Dr. Microcomputer"(MAIKON HAKASE), was designed as the consumer electrical appliance that nobody think from the product's character. First, it was low price. TK-80 was 88000 yen, TK-80E as cost-downed was 67000 yen, but MZ-40K was 24800 yen. The other product's user needed to buy a case and put into it, but MZ-40K had a plastics case(it was only stand that stay both sides) and acril board. Power supply was general AC adopter. And it had speaker and could play music automatically or become organ, and the user needed not make any programs because all programs was included into CPU. It seems that the only part of originally character was that this was a kit.
The next table is included functions into CPU.

Function Setting addres Execute addres Discription
Clock A blank Set seconds and frequency of power line
B blank Set hour and minutes
Timer 9 blank Set timer
blank 8 Beep buzzer by reached time
7 7 Play music by reached time
Sensor B 1 Initial setting of sensor 1 counter and display counter of sensor 1
1 1 Play music by input of sensor 1
2 2 Play music by input of sensor 2
3 3 Play music by input of sensor 3
4 4 Play music by input of sensor 4
5 5 Play music by input of sensor 5
6 6 Play music by input of sensor 6
Auto play F000 blank Music data
0 blank Beginnig addres of music data
E 0 Tempo and start play
Organ blank C Sound by push ten keys
Telephone
account
E D Set second at per charge and count
Game F000 blank Set parameters, and start by long push into switch

There is some game of dice, roulette, big-game hunting, car race, the emcampment, and message memo discripted in manual. The message memo is only written and read messages by RAM in ASCII code, and the other game is displaied the number in continuously accessed address when user detach the switch for game with randomness of human's oparation. There were contrived with simple functions.

MZ-40K, was designed for easy enjoying for the beginner specially, didn't sell well after all. For one of reason, it seems that SHARP made a mistake in product's concept. Because it was designed too simply for beginners, the users could not step up higher. Already the programming handbooks were published for TK-80. They could not apply these books by MZ-40K without function of program. The user hankered for TK-80 but he had bought MZ-40K after all, then he might think that he was deceived.
Further, it may have relation that microcomputer boom was dying down. Already NEC sold the Basic Station for TK-80, it wasn't need to punch the ten keys to hexadecimal codes for enjoying microcomputer. Furthermore, the product, COMPO BS as mostly complete personal computer, was begun to appear, and oversea's personal computer was begun to import however it was expensive. The personal computer age was coming soon.

By reason of those, MZ-40K became a rare machine that an insider knows. But, part division of SHARP seized an opportunity of making products for consumer, not only parts work. And it is succeeded to MZ-80K soon after.

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