Z-Tape

WORDMONGERS LIMITED
Tape streamer software for the Z88

Introduction

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.

Important basic concepts

Saving data

Saving data to a tape involves a number of processes. Firstly, the data, which are a series of 0's and 1's, are grouped together in pre-determined block sizes. The blocks are then converted to on/off pulses and sent through the serial port to the cassette tape. These pulses can be heard as a series of squelches.

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.

Although tape cassettes are much less expensive now than in the past, very cheap tapes should be avoided.

As with all backup systems, any vital data should be stored at least twice.

Z88 Filer

The Z88 FILER popdown is the internal route to file handling on the Z88. In order to keep things consistent, the FILER system has been emulated as closely as possible in Z-Tape. Therefore, files can be listed and marked in a fashion similar to the filer. However, some differences exist between FILER and Z-Tape.

Backup Facility

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 wildcards 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.

Quick Start Guide

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

This will initiate a 'SAVE TO CASSETTE'.

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.

The prompt will appear asking for the name of the file to be loaded (fetched from tape). Press * ENTER and rewind the tape.

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.

Alternatively, selecting INDEX or any Z88 popdown or Application will exit Z-Tape. Since Z-Tape is itself a popdown, it will not be left as a suspended application.

The Menu

Z-Tape operates in a similar fashion to existing Z88 popdowns. It can be called from the Applications INDEX by highlighting it with the cursor, or by entering □ J at the keyboard. In either case the commands menu will contain the options available.

The commands are:

The following sections deal with each option in turn.

When Z-Tape is invoked, the Commands will appear on the left, as usual, with the file names of the default device and directory in the middle window, just as in the FILER.