Getting started
Quick test
If you just want to have a quick look without any hardware
modifications, you can go to a BASIC prompt using the built-in easter
egg:
- In the blue “READY.” screen wiggle the joystick left-right or
up-down very quickly.
- Then, LOAD“$”,8 instead of LOAD“*”,8,1 will be run, giving a
list of programs that can be run using the joystick, most notably
the BASIC Prompt which features a keyboard emulation that can be
accessed with the joystick.
Connecting the DTV to the outside world
To get data on the DTV, you need to add at least :
Power supply
Make sure the keyboard gets 4.5 to 5 Volts DC. 6 Volts (4x1.5 Volts
normal batteries) will probably fry it!
- Use a regulated/stabilized 5V DC power supply, 500mA or more
- USB chargers and some mobile phone chargers should be okay.
- Or rechargeable batteries (4x1.2V)
- Or a standard/non-regulated power supply (12V,…) with a extra
regulator
to 5V. Add a 1N4148 protection diode pointing from pin 3 to pin 1
(see here
(German)
why )
The DTV board is designed to work with a 3.3V voltage. The built-in
red power LED works as voltage reference in the DTV’s 3.3V
regulator circuit - so don’t
remove or replace it with a different LED type (1.8V forward voltage
needed - especially blue LEDs are not suitable). Replacing this
regulation circuit with a linear regulator is possible but seems to
reduce power consumption only by about 15% (from ~166mA to ~140mA -
PETSCII forum
thread
).
The DTV power switch wiring is a bit unusual. It connects DTV
ground (“E-”) to battery ground in “On” position. In “Off” position,
it connects the 3.3V DTV line to DTV ground via a 100 Ohms resistor
(“Dis”), probably to discharge capacitors. Keep this in mind when
attaching peripherals whose ground connection might bypass the power
switch.
Transferring data to the DTV
See Transferring programs to the
DTV.
DTV Hardware Mods
please add only ‘best’ links here - this is not intended as a
‘complete’ link collection
- Simple colorfix for
DTV2/PAL. In a nutshell: Add three 220Ω SMD resistors (0603
packaging; 0805 also fits) in parallel to the existing R16, R20,
and R24. Also, add one 330Ω resistor (a standard wired one works)
from the point between R14 and R16 (the side of R16 pointing away
from R20 is okay) to ground. Use a grounding point a bit away from
the audio line to prevent noise. 166Ω can be measured on each of the
additional resistors if soldering is okay. Reported to work even
better than the ‘true’
colorfix as
suggested by Mr. Latchup which requires replacement of 17 (!) SMD
resistors. Good SMD soldering skills and equipment needed!
Comparison
of palettes. Note that for perfect colors the software palette needs
to be changed, too (DTVSlimIntro can do
this).
- S-Video
output for clearer video (for Hummer. Remove
C10
for DTV2)
- DTV2 PCB boards:
Keyboard/Floppy/Joystick/Video/Audio/Userport solder
points picture. If you
want to change the casing: bottom side solder
points are more
accessible.
- Make sure you patch the kernal with kernal
patcher before doing the userport mod
since the standard kernal sets PAL/NTSC mode depending on the
userport’s wiring.
- Joystick connector pinout: JoyX0=Up=Pin1, JoyX1=Down=Pin2,
JoyX2=Left=Pin3, JoyX3=Right=Pin4, JoyX4=Fire=Pin6, Gnd=Pin8,
+5V=~Bat+=Pin7
- Bat+ is the batteries’ positive pin so it’s about 6 Volts with
normal batteries (too much for a keyboard!) and about 4,8 Volts
with rechargeable batteries
- IEC/PS2/S-Video/Joystick
pinout
Case Mods
Additional hardware
also see Peripherals and Add-ons