WORDMONGERS LIMITED

Tape streamer software for the Z88

...

The Wordmongers Z-Tape program is designed to provide general data backup opportunities for the Z88 with a cassette recorder.
In addition, the software includes a routine which will run a machine code program from RAM.

...

Two elements are crucial to the proper transmission and receipt of the noises and both are related to timings. The data sent out from the Z88 goes at a set speed which must remain constant when the data are read back. For this reason the health of the power supply to the tape recorder is of utmost importance. If batteries are used, they should be checked regularly. Whenever possible, a mains supply should be used.

Equally important is the quality of the tape in use. The recommended tape is a C30 with 15 minutes on each side, or a smaller tape. Larger tape may stretch and distort. The C30 tape is sufficiently robust not to stretch too much in use. Thus the apparent speed of the data on the tape is less likely to distort.

...

Because Z-Tape is designed as a backup facility, any saving to tape is done as a complete operation including a catalogue of the files saved. Individual files should not be added to an existing backup tape. Any save operation is a one off event for a tape. Incremental saving is not recommended.
For this reason, any saving is done by file name or group of files. Files to be saved in any one save can be marked as in the FILER or selected on the basis of wild cards such as *. See SAVE TO TAPE, below.

By careful management of a tape, a second set of files may be saved to a tape with its own catalogue. However, it is then up to the operator to ensure that the rewind brings the tape to the correct position when doing anything which involves the catalogue section. This is not recommended.
Unlike saving to disk on a PC, saving a file to tape is a one way process. The Z88 sends the data out of the serial port and has no way of knowing whether the data has landed safely, if at all. Therefore the verify option is an important routine which should be used whenever a set of files is saved.
If the verify routine is not tried, the first indication of damage will appear when that file is loaded back to the Z88.

...

The Quick Start Guide is designed to be a brief exposure to the save and load facilities of Z-Tape. It is not comprehensive and is no substitute for the rest of this manual.

QSG 1

With the INDEX on display on the Z88, open the clear perspex cover labelled '1 2 3', and insert the Z-Tape application ROM in slot 3. Close the perspex cover. (For details of other options about how to position ROMs see Appendix 2).

Move the cursor bar up and down on the APPLICATIONS INDEX until it is highlighting the Z-Tape application.

Press ENTER to run Z-Tape.

QSG 2

The screen will display the Z-Tape front screen with a Wordmongers copyright message in the screen window on the right.

Connect the Z88 to the cassette recorder using the cable supplied. Of the two JACK plugs one will be plastic (or a BLACK plastic), and the other one metal (or RED plastic). The Metal (or RED plastic) one is for the Mic socket. i.e. M for M.

QSG 3

Select a file for saving to tape by moving the cursor bar to any one of the files whose name is displayed on the central directory window. With the selected file highlighted, press ENTER. A small mark will appear next to that file.

Also note that the right hand window will now display a value for the number of bytes in the file marked, and the size of tape required to hold the marked file.

QSG 4

having selected a file, press ◇ C S

...

An instruction will appear on screen saying that the tape recorder should be switched on with the RECORD button depressed. When this has been done, press any key to commence the saving of the file to the tape.
Press ESC if you need to abandon the save.

QSG 5

When the save is complete, stop the tape and rewind. From the Z-Tape menu press the command to verify, ◇ C V

A prompt will ask for the file name to be verified. Press * ENTER then start the tape.

QSG 6

Now to LOADING a file or FETCH FROM TAPE. Insert the tape with the required file into the cassette recorder and ensure that it is fully re-wound.

QSG 7

Press ◇ C F to initiate a Fetch from Cassette.

...

Start the tape, without the record button depressed this time. A filename and counter will appear on the screen as the file is received. As soon as the required file or files are received, the Z-Tape menu will return.

QSG 8

All that remains is for the retrieved files to be examined.

QSG 9

Press ESC to kill the Z-Tape application and return to the Z88 INDEX.

...

After the tape has been started and has run past the leader, the catalogue block(s) will be loaded to the Z88 and displayed. As soon as the catalogue of files is displayed, the tape may be stopped and
rewound.

Cassette Save (Save to Tape) - ◇ C S

All files to be saved to tape in a single operation MUST BE on a single directory.

Marking the files

The primary method for selecting files for saving is to use the cursor to move round the file names list and mark each file in turn. The first file is marked by pressing ENTER or TAB. Subsequent files are marked by using the SHIFT+ENTER combination or the TAB key.

...

With a set of files marked in this way, the SAVE TO TAPE option can be selected by entering the ◇ C S command, or by moving the cursor bar to the 'SAVE TO TAPE' option on the commands list.

Wild Cards

An alternative way of saving involves the use of file names. If no files are marked, as described above, the SAVE TO TAPE function may be called using the sequence or by pressing the MENU key and moving the cursor to the required option.

...

(See "Saving Data" section above.)

Cassette Fetch (Tape) - ◇ C F

All files collected from Tape will be downloaded or fetched onto the currently selected device and directory.

...

1. LOAD ALL

2. LOAD ONE

3. LOAD NEXT

LOAD ALL

To specify ALL files the necessary response is

...

Firstly, a catalogue of the tape could be obtained (see above ◇ C F) and examined for duplicate file names. Alternatively, a new clean sub-directory could be set up to take the files from tape and any duplicated files could be compared after the download is complete.

LOAD ONE

To specify a single file to be brought from tape, the file name must be entered here in exactly the same form as it was stored. i.e. file name only without any device or directory name.

...

In this instance, the catalogue is not examined at all. The software will start at wherever the tape is and will read whatever comes from the tape until the header block for the required file is encountered. At that point the downloading will commence until that single file is collected. The 'STOP TAPE' message will then appear.

LOAD NEXT

Enter a ! (exclamation mark) at the file name prompt. A choice reminiscent of the LOAD "" on Sinclair Spectrums. The first file found by the software will be restored to the Z88. If the tape is left at an intermediate point in the middle of a file the download will begin at the start of the next file.

Execute the fetch

After specifying the files to be read onto the Z88, the screen will split onto two halves. The left will show the number of files to be retrieved from the tape with the name of the first file expected. If the * or ! options are used, a series of ?'s will appear. The word WAITING will also be there.

...

After completion, the Z-Tape Commands Menu will return with the default directory displayed.

Cassette Verify (File) - ◇ C F

This option will appear very much like the FETCH FROM TAPE option in that a prompt will appear asking for the name of the file to be verified. The same symbols may be used here as for FETCH FROM TAPE, namely

...

The saving operation should be executed again.

Select DeVice - ◇ S V

This routine operates in a manner very similar to the FILER. When selected, the current device title will be displayed. This can be over-typed with the required new device title. The selection is complete when the ENTER key is pressed.

An additional way to select a device is to scroll round the Z88 device addresses using ◇ ↑ and ◇ ↓. Even if there is no RAM.3, it will still appear on the scroll round as an empty directory. If an absent RAM pack is accidentally logged an error message will appear when any saving is to be done.

Cable Schematic

...

Further Reading

• Reverse engineering Z-Tape for the Cambridge Z88 by Ben Ryves.