TNS HC-08

Also called Home computer 8bit.It was manufactured from 1988 by JZD AK Slušovice. The computer was inspired by or was successor to TNS GC. Hardware is based on U880D @ 3 MHz.Operating system running on the computer: TNS-DOS(TurboDOS).

Parts of this topic may be machine translated.

price from 25,000 CZK

Connectable to the TNS-NET network, the HC-08 enables system booting over the network.

Keyboard identical to TNS HC-16.

Variants

Periphery

BootROMs

A total of 3 variants have survived:

For variants with two 2716 memories, the first is from address 0x0000, the second from address 0x1000 (i.e. there is a gap, apparently due to the plan for a larger circuit). The code first copies the contents to RAM, then the ROM is disconnected from the memory range.

Description from documentation

It is possible to install an operating system on TNS-HC computers

either from 5 1/4" floppy disks directly attached to it,

or within the network via fast or slow

lines from another computer on the network.

By "fast line connection" we mean

connecting TNS computers with a coaxial cable using modules

UPP-NET.

By "slow line connection" we mean

serial current loop - channels A and B, controlled by the module

ASK or QASK.

Channel A current loop and fast line are controlled

common technical equipment and only depends on the settings

switches in the TNS-HC computer, which one will be controlled.

For this reason, they cannot be connected at the same time.

After turning on the computer, or resetting it, the bootloader

it announces by printing the opening header and then starts on its own

to find out if there is a floppy disk in any disk drive.

First it tests drive 0, then 1. If the disk really

finds, tries to install a special boot program from it,

which is stored in the reserved tracks of each system

floppy disks. If the disk found is indeed a system disk, it will boot

with the operating system. Otherwise, it will attempt to install

system failed (it "freezes").

If the bootloader is not found in any disk drive

diskette, it will ask where to boot the system from:

xxx asks where to boot from (A,B,L,X,Y,0-31 + Take) ?

The value "xxx" is the number of the given TNS-HC computer set

switch.

The user is expected to enter one of the following

options:

A - the bootloader will try to boot the operating system from disk

units 0.

B - the bootloader tries to boot the operating system from disk

units 1.

F - the bootloader will try to boot the operating system first

from disk drive 0. If not found in that drive

diskette, it will try to boot from drive 1 as well.

X - the bootloader switches to channel A of the current loop

Y - loader switches to channel B of the current loop

L - the bootloader switches to fast line. This state is

set by default.

dd - number under which is the remote computer from which

the system will be loaded, I know it in the network. It is entered

decimal in the range 0 - 31.

If you make a mistake when entering an option, you can correct yourself

using the [<-] key.

When booting from a remote computer, first is required

determine whether the operating system will boot from fast or

slow lines and possibly determine the channel of the current loop.

As mentioned, by default it is set to boot from

the fast line that is used most often. Line designation

done by choosing L, X or Y. The loader is thus prepared for

booting from the required line and again asks where from

should boot the operating system. However, it is now waiting for input

numbers of the remote computer from which the system will be booted.

The bootloader always tries to boot the operating system first

from floppy disks. However, so that we don't have to wait when booting from the line,

until the bootloader detects that they are not inserted in the disk drives

diskettes, we can press the desired option at the same time

by pressing the [RESET] button. After releasing both buttons,

the bootloader will try to boot the system as per our request.

= Examples =

Loader TNS (FWLP) - in 1.2 JZD Slušovice 1989


Floppy 0
Floppy 1
003 asks where to introduce (A,B,0-31 + Take) ? 2
The line is connecting...ok
reading the operating system ... ddd
I'm handing over control to OS

After turning on the computer or resetting it, it displayed

loaded your opening header and started to find out,

whether floppy disks are inserted in the disk drives.

Follows this sequence though 5 1/4" units

they are not physically connected to the computer. The bootloader though

posted a query from where to start, from which we can conclude,

that it could not find the floppy disks in the drives. We request to implement

system through the default fast

lines from computer number 2. The loader first tried,

whether the connection can be established. He succeeded, that's why

started loading its own system file SYS.SYS. After

loading it, handed over control to the system.

2) Loader TNS (FWLP) - in 1.2 JZD Slušovice 1989

Floppy 0 boots OSBOOT

OSBOOT V 2.01 (C) SWS/TPS Slusovice

Now the bootloader has found the system disk in drive 0

diskette, which can be recognized by the fact that it is from the diskette

succeeded in introducing a special OSBOOT boot program.

He first wrote his header and then on the diskette

looked for the system file SYS.SYS to which he passed po

introduction of management.

3) Loader TNS (FWLP) - in 1.2 JZD Slušovice 1989

Floppy 0

Floppy 1 boots OSBOOT

The bootloader tested for diskettes in the drives. IN

it didn't find the disk in drive 0, it did in drive 1. It isn't

however, it's the system disk because it's bootable

failed to boot from it a special boot program

OSBOOT. The only solution to this error condition is

computer reset.

4) Loader TNS (FWLP) - in 1.2 JZD Slušovice 1989

Floppy 0 boots OSBOOT

OSBOOT V 2.01 (C) SWS/TPS Slusovice

SYS.SYS not found

Even in this case, the diskette is not inserted in the drive

0 system because there is no system stored on it

SYS.SYS file.

5) Loader TNS (FWLP) - in 1.2 JZD Slušovice 1989

Floppy 1 selection error

In this case, we are already in the process of resetting the computer

requested to boot the system from unit 1. They pressed

we are the [RESET] and [B] buttons at the same time. We can do that

infer that the bootloader tried to boot immediately

system from the floppy disk in drive 1 without prior to that

tested unit 0. However, because in this unit

there was no system disk, the bootloader displayed an error

reporting.

6) Loader TNS (FWLP) - in 1.2 JZD Slušovice 1989

011 asks where to introduce (A,B,0-31 + Take) ? 5

The line is establishing a connection... - communication error

011 asks where to introduce (A,B,0-31 + Take) ?

The first thing that can be deduced from the texts in this example is

the fact that we already requested to boot the system during the reset

via the fast line. We pressed at the same time

[RESET] and [L] buttons. The bootloader tried to follow up

connection, which he failed to do. In this case

look for the fault directly on the line.

7) Loader TNS (FWLP) - in 1.2 JZD Slušovice 1989

Floppy 0

Floppy 1

008 asks where to introduce (A,B,0-31 + Take) ? 1

The line is connecting...ok

reading operating system ... 000

If the bootloader succeeds in establishing a connection, it will try

load the system file SYS.SYS. If the file

does not load (the counter remains zero), it is necessary

look for the fault directly on the computer where the system is from

introduce.

I/O ports

Chipselect signals are generated by 74154 (IC104)

Output 74154 I/O Range Meaning / Circuit Note
CS0# 0x3C-0x3F -
CS1# 0x38-0x3B S2
CS2# 0x34-0x37 - Supposedly S3 !!!
CS3# 0x30-0x33 S4
CS4# 0x2C-0x2F PFD OFF
CS5# 0x28-0x2B PPIMAP
CS6# 0x24-0x27 MAPF
CS7# 0x20-0x23 DEFMAP
CS8# 0x1C-0x1F OFF
CS9# 0x18-0x1B FDC card
CS10# 0x14-0x17 FDC card
CS11# 0x10-0x13 PPI 1 - MHB8255A
CS12# 0x0C-0x0F SIO - IC86 - UA8560D Channel A (CTC1, Channel 0): TNS-NET / Fast Line, Channel B (CTC0, Channel 1): Serial Printer
CS13# 0x08-0x0B PIO - IC51 - UA855D
CS14# 0x04-0x07 CTC1 - IC88 - UA587D
CS15# 0x00-0x03 CTC0 - IC87 - UA587D

Computers derived from TNS HC-08

The following computers were inspired by or derived from TNS HC-08:

References