Sun Ultra 5

It was November 2003 and I was in Tokio after a conference, so what is one of the geek places to visit in Tokio ?, ...
(if you don't know the anwser it should be that you have not been in Tokio and not a computer collector ;-).

Akihabara, is an area of Tokio full of electronic equipment, new and also used /old, so it was the perfect place to buy some olf stuff. After visiting the place I bought a Sun Ultra sparc5 for 6,300 Yens , about 50 Euros in 2003, so it was a cheap.

 The problem is, "how to carry a Sun ultra Sparc 5 home ?", (and cheap / free ) , the machine weight about 8kg, so it was not good to put inside the baggage.

The reply is easy , as "cabin baggage", so here are two pictures of the machine prepared to flight home:

Both pictures were taken in the Hotel room just before leaving, it was quite heavy, but fortunately I don't need to walk too much to reach the airport.

 About the machine it wood to remember that was one of the "cheap Sun", (with IDE hard disk & cdrom,  VGA video output and so on,) but with a Ultra Sparc chip , able to run the recent Solaris 10
(if you have enought RAM).

 I will try to put more pictures of this machine at home soon.

16Kb memory expansion for ZX81

The original sinclair ZX81 has only a 1kb memory of RAM, so it was quite difficult , but not impossible , to produce any big program, obviously soon there was memory expansion for them and one of those modules was the 16Kb memory extension (usually any image of this blog , compressed and so on it's too big to fit in those memory modules, but in a few years ago 16 kytes of RAM where a lot of space .

As a curiosity , the three first models of sinclair used the same processor, the zilog z80, so where able to access up to 64Kb of RAM (2^16) , so with the different size in their ROM size (BASIC interpreter, Input/Output routines, etc), produces that the total RAM size of the machines where bigger in the first models (up to 60Kb in the sinclair ZX80, 56 kb in the sinclair ZX81 and only 48Kb in the last model sinclair Spectrum.

After the sinclair spectrum the other models (sinclair spectrum 128, +2, and +3 ) used a technique named "pagination" to share a memory space between different memory banks allowing to have more than 64kb, but not at the same time.

casio FX-702P

Another calculator from casio, with a BASIC interpreter allowing to develop your own programs, this model has the unusual feature of not using a QWERTY keyboard, and keys are aligned following their alphabetic order in a 7x4 rows

Sinclair ZX-interface 2

Sinclair made some interfaces to enhance the posibilites of the most successful product, the Sinclair Spectrum , those interfaces include the interface 1 (allow to connect to microdrive units and serial RS-232 interface ) , the ZX-printer interface (thermal printer and this interface, named "interface 2".

This interface allow to connect two joystick to the spectrum , using the "Sinclair type joystick", that usually links the numeric keys to the joystick and the other facility provided by this interface was the use of memory cards with games and utilities that allow to start running applications and programs without loading them from tape.

Unfortunately the cartridges were quite expensive so few games were produced in this format, also it was ROM (read only memory) so people can't save their own games in them.

Quantum Lap , Sinclair QL

In 1984 sinclair launched the QL, Quantum Lap, as a computer aimed to a more professional sector, it has some revolutionary aspects (it was based in the 68008 Processor, a 32 bit processor with a 8 bit interface, ( 8 bit connectors and hardware was cheaper and price was always one of the basic features of Sinclair machines).

The system has a revolutionary "multi tasking BASIC interpreter", 128 Kb of RAM and instead of using the expensive floppy drives (remember 1984 , 5' 1/4 floppy were still common in 1990, or the slow and sequential tape system (like the spectrum ), uses their own technology , the "microdrive"

Microdrives were in fact small tapes that were inserted in the unit and must be formatted to be ready, to use, allowing to store about 85kb of data.

As the tape runs quite fast, the tape must be formatted in sectors , so it can be used as a random
device (instead of the typical sequential tapes).

Here is the a view o the unit, the QL came with two units

As this machine was targeted to the profesional market it come with a full "Office Software", in four
microdrives and other blank microdrives.

The package was "Quill" (the word processor), Abacus (spreadsheet ) , Archive (Data Base) and Easel (Graphs) that provides most of the usual needs for an normal user.

The machine provides two serial interfaces and was able to connect to other QL machines using their own network protocol (similar to token ring), and be connected to a normal TV or a computer monitor, also has serial interfaces ,

The three first sinclair

The first years of the 1980 decade was dominated in Europe by sinclair, the company launch a new model of computer every year, changing from the "white" ZX80 , with 1 Kb of RAM, then the ZX81, with provided a better BASIC support , but still only a 1K of RAM , and the next year the Spectrum with
Color !! , and 16Kb of RAM (or 48K in the upper model) .

Sinclair Spectum 48K aka gomas

This is the FIRST model of computer that I got, as I told before I "upgraded" the sinclair 48k to Sinclair + (the one two or three post before).

This machine is a gift from a college  after he discovered my not so hidden Computer Diogene Syndrome (recollect all kind of old computers ;-)

About this machine there is few more things to say perhaps that the best Spanish Company started developing games for this platform (Dinamic ) and that more than a generation of Computer Engineers and technical people in Spain grew and learn to play games (and sometimes also some BASIC language ) with it.

The machine was too popular that some radio station used to broadcasts games that the user save in a normal tape , loading the games from the tape.

here you can see, from left to right the power connector, expansion slot and the plug for saving and loading files from a normal tape.