Programmable calculators are calculators that can automatically carry out a sequence of operations under control of a stored program, much like a computer. The first programmable calculators such as the IBM CPC used punched cards or other media for program storage. Hand-held electronic calculators store programs on magnetic strips, removable read-only memory cartridges, flash memory, or in battery-backed read/write memory.
Since the early 1990s, most of these flexible handheld units belong to the class of graphing calculators. Before the mass-manufacture of inexpensive dot-matrix LCDs, however, programmable calculators usually featured a one-line numeric or alphanumeric display. The Big Four manufacturers of programmable calculators are Casio, Hewlett-Packard, Sharp, and Texas Instruments. All of the above have also made pocket computers in the past, especially Casio and Sharp.
Many calculators of this type are monochrome LCD, some are four-color (red or orange, green, blue, and black), or, in the case of some machines at the top of the line as of January 2022 color similar to monitors displaying 16 or 32-bit graphics. As they are used for graphing functions, the screens of these machines are pixel-addressable. Some have a touch screen, buzzers or other sound producers, internal clocks, modems or other connectivity devices including IrDA transceivers, several types of ports for peripherals like printers, and ports for memory cards of a number of types.

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  1. D

    OSO unvented hot water cylinder - Wi-Fi / programmable control

    Hi all, I have an OSO Direct 210 hit water cylinder installed in my home, with 2 switches (on/off; and boost). The boiler is for hot water only (rads are electric). In the 5 years that I’ve lived at this property, I’ve never once turned the boiler off; however, with soaring energy prices, I’m...
  2. G

    Polypipe Programmable Room Thermostat - PB PZP

    I've had a couple of these battery powered thermostats fail and currently looking at finding replacements but I'm fairly sure they are now superseded? Can anybody advise on other programmable battery powered units that could be used instead? I'm assuming the others may well start to fail in the...
  3. R

    ESI series 6 programmable thermostat

    Hi all I have a main eco compact 30kw combi boiler installed. This is using weather compensation (baxi ifos) and salus iT500 controller. The salus is starting to play up so I am in a dilemma. Do I replace the salus with a hive or similar and continue to use the weather compensation, or do I...
  4. P

    Replace ancient Honeywell mechanical thermostat with a Honeywell T3R

    I would like to replace my ancient Honeywell mechanical thermostat with a Honeywell T3R PROGRAMMABLE THERMOSTAT I have three wires in the old thermostat. Please see the first three photos. 1 Red 3 Yellow 2 Blue are these 1 Live 3 Live return (Switched) 2 Neutral Could I configure it as in...
  5. siricosm

    Programmable TRVs for cast iron radiators

    Does anyone know of programmable TRVs that would not look out of place on period cast iron radiators? Even finding regular TRVs is tricky, all the ones that "look good" seem to be very expensive and very good quality.
  6. S

    Easiest upgrade to a wireless Honeywell programmable controller

    One of the temperature buttons has become unresponsive on the wireless controller. I cleaned the pad with switch cleaner, no improvement. I've seen that Wolsley seem do a rebranded version that's cheaper but I quite fancy Hive etc. Will any smart thermostats work with the existing boiler...
  7. king of pipes

    Simplest programmable stat for the over 70's

    Opinions please ladies and gentlemen I have a elderly couple who how can I say it ? are being rather challenging to please needs to be RF Regards kop
  8. B

    programmable thermostat to control a Mixer Valve.

    I want programmable thermostat to control a Mixer Valve. This to provide CH flow temperature from 30C to 70C from a thermal store tank at 80C
  9. B

    I want programmable thermostat to control a Mixer Valve.

    I want programmable thermostat to control a Mixer Valve. This to provide CH flow temperature from 30C to 70C from a thermal store tank at 80C
  10. A

    Wiring Programmable Thermostat

    Hi Guys. I have a Worcester Greenstar 30i boiler and when we moved in we had our old Thermostat removed and a Nest installed, I have now removed the Nest ready to put the old thermostat back on (Honeywell CM907) but don't know where the wires are meant to go. I think I've done the boiler bit...
  11. Z

    Programmable cylinder thermostat

    Currently have Nest system. Would really like to be able to have a programmable cylinder thermostat that allows different temperatures at different times. Realise I need to have 61 degrees for a couple of hours once a week. Would want low temperature (e.g. 40 degrees at lunch time for the...
  12. P

    Programmable room thermostat for ideal logic

    hi guys. After recommendations for a programmable room thermostat. Preferably wired and if possibly weather compensation. It is going on a older model ideal logic combi.
  13. P

    Best programmable room thermostat for old idea logic

    hi guys. Customer is after a good programmable room stat for an old ideal logic. Preferably wired and preferably able to have weather compensation aswell. Thanks guys.
  14. J

    How to set a time EHE0200361 RF Programmable thermostat

    Can anyone be so kind as to help me out. I've read the instructions for the above thermostat: and if I'm reading it correctly, it doesn't provide the option of being able to set the gas to come on at a...
  15. H

    Programmable wireless Room Stat for Vaillant & WB

    Has anyone tried the plug in programmable wireless room stat from SALUS for both WB (ST620WBC) and Vaillant ecotec (ST620VBC) combi boilers at a fraction of the cost of their own offerings.
  16. M

    Baxi combi boiler – recommended wireless programmable unit

    Hi We have a Baxi combi boiler and we need to change the thermostat. We’d like a wireless 7 day programmable unit. We’ve been recommended Honeywell but the reviews for their 7 day wireless one aren’t that great. Just wondering what other people are using. Thanks Michael
  17. M

    Vaillant programmable room stat VRT360f

    on Friday I had the hot water cylinder replaced as there was a leak in the old coil. On completion plumber asked me to use programmable room thermostat, Vaillant VRT360f, that is WI-FI connected to VR65 Control Centre to heat water. Boiler fired up and port valve opened, all good but after...
  18. J

    Is there a programmable stat that can also do immersion heater?

    Hello, Looking for help with finding a suitable controller. Customer has oil Aga for central heating and hot water - simple enough. However over the summer months it gets shut down and any heat requirements are met by wood burner and hot water is produced electrically via cylinder immersion as...
  19. plumb_know

    programmable room thermostat

    Hi Everyone, looking for some advise on central heating controls please, don't have much experience with them but soon to be gas safe and need to start learning more. I have a customer who has called me because they have bought a property and they have a british gas up2 model time control...
  20. B

    Horstmann Programmable Room Thermostat T50 - Programme Issues

    I have a Horstmann Programmable Room Thermostat T50 which works fine for the first programme and the last programme of the day – the lights come on the receiver fine but all the programme settings in-between don’t work – the receiver doesn’t light-up even when the thermostat is near so I have a...
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