Applies to IBM or Toshiba Retail POS Keyboard, Retail POS Keyboard w/ Card Reader, Retail POS Keyboard w/ Card Reader and Display, Retail ANPOS Keyboard w/ Card Reader and Modifiable Layout Keyboard
Notice 2022-04-24:
This wiki page is a work in progress and is subject to vast improvements!
![Various Retail POS Keyboards<a class='source-link' href='/wiki?id=modelmretail#Sources'><sup>[ASK]</sup></a>](resources/images/model_ms/collage_rpos_model_ms.jpg)
The IBM/Toshiba Retail series of POS (RPOS) input devices were the first IBM point of sale keyboards that made use of IBM buckling rubber sleeve key-switches. Announced in June 1993 for the IBM 4694 Point of Sale Terminal[1], the RPOS series is made up of five Model M-designated keyboard designs with both common features and notable differences in their DNA, including the 50-key M7, M7-1 and M8, 116/117-key M9 ANPOS and 133-key M11 matrix keyboards. The RPOS series was very long lived as it was in production for at least 21 years, with Toshiba branded examples known after Toshiba TEC bought IBM Retail Store Solutions in 2012, forming Toshiba Global Commerce Solutions (TGCS)[2].
After the RPOS series was enhanced with new keyboard designs introduced in the early 2000s, the Modular POS (MPOS) series of Model M extended family ("Model M-e") keyboards started to replace the Retail series from 2008 onwards. Whilst the official Model M designation were produced, these modern MPOS keyboards are evolutions of RPOS series and early M-e designs and share much of their core DNA.
The RPOS series was announced on 1st June 1993 for the IBM 4694 POS Terminal model 001 and consisted of five keyboard designs[1], initially manufactured by:
These five keyboards in turn replaced IBM's 4683/4684 era keyboards that were manufactured by IBM itself, Key Tronic and SMK. All five keyboards used RS-485 serial for general communication and PS/2 for scancodes, the former fact meaning they are not natively programmable with a regular PC. By December 2001, IBM had introduced USB versions of the RPOS keyboards with its IBM 4800 SurePOS 700 series[3]. This included:
Production started by at least the previous year as examples of USB-compatible RPOS keyboards were produced as early as February 2000. Such RPOS keyboards typically have a part number in range of 86Hxxxx[4].
The RPOS series was the first IBM POS keyboards to adopt IBM buckling rubber sleeve (known simply as [IBM] buckling sleeves) key-switches. These were once IBM's primary portable computer key-switch technology in the first half of the 1990s, being adopted on famous IBM machines such as the IBM Personal System/2 L40SX (Model M3), IBM ThinkPads 700, 720, 750 and 755, and IBM RS/6000 Notebook 860 (Models M6 and M6-1). Unlike generic rubber dome key-switches, the rubber component in buckling sleeves plays no part in pressing down on the membrane. Instead, the design offloads this duty to rods on the keycaps or barrel-mounted sliders (depending on specific implementation) that descend through the keyboard's key-switch barrels. This effectively eliminates the mushy feeling of bottoming out on rubber dome keyboards since the actuation interface is more solid, whilst still keeping the design tactile and relatively quiet. IBM buckling sleeves are very snappy and quite tactile with what's perhaps best described as a medium stiffness feel relative to other key-switch designs.
The RPOS series' adoption of IBM buckling sleeves was presumably the reason why they bear Model M designations. All RPOS keys use standard gauge sleeves and most RPOS sleeves are clear-translucent coloured. This sleeve gauge is interchangeable with all Model M3 and M4 and most Model M6 and M6-1 sleeves. When RPOS was produced in the Americas by Lexmark (United States) or Maxi Switch (Mexico) until around 2002, the specific type adopted is now known as early (barrel slider actuated) POS-type IBM buckling sleeves which use the same crosspoint keycap mount that attachs to a barrel-fixed slider as the Models M6 and M6-1 portable computer keyboard assemblies IBM used on most of their early ThinkPads. When production was moved to the Far East to XAC (Taiwan) and XSZ (China), what's known as late (rod-actuated) POS-type IBM buckling sleeves were employed that kept basically the same sleeve element but simplified the keycap mount to something more similar to what IBM used with the Models M3, M4 and M4-1. The only minute physical difference to the sleeves are slight grooves on their outer rims but this doesn't significantly alter the key-feel or sound and only late POS-type hosts have them.
RPOS series cases use a PC and ABS copolymer with two possible resins listed on the keyboard case's embossed stamp; Bayer's Bayblend FR-110 and SABIC Innovative Plastics' CYCOLOY C2950, both frame-retardant plastics[6][7]. The plastic is relatively sturdy with the Models M7, M7-1 and M8 exhibiting minimal flex but the M9 and M11 having a little. Some RPOS keyboards have been observed to have yellowed over the years but it seems this isn't a universal occurrence, meaning any environmental conditions needed for the degradation is more specific than other plastics that are known to more often yellow and yellow to a more severe degree such as some non PC blended ABS plastics. The case is also textured, but only slightly and nowhere near the level of most buckling spring keyboard cases. That said, the cases are wedge-shaped just like its 1980s Model M ancestors but are more angular. All RPOS keyboards are styled similarly to each other to maintain a uniform resemblance and IBM-era examples have a oval badge on the rear-facing side of the keyboards.
The internal keyboard assemblies are a Model M staple of three distinct layers; the barrel plate, the membranes and the backplate. The barrel plate sits atop facing the user and is used for guiding the location of individual key-switch components such as the buckling sleeves and the keycaps on top of them above the membranes' contact points. Due to the uniqueness of some of the RPOS designs, there's no standard uniform barrel plate and only the M7 and M7-1 share the same barrel plate design. That said, the Model M9 has a universal alphanumeric barrel plate design for both US English and rest of world layouts. The membranes are a part of the key-switch system used as the circuitry to be actuated by the barrel sliders (Lexmark and Maxi Switch made RPOS keyboards) or the keycaps' rods (XAC and XSZ). Finally, the backplate provides rigidity.
Unlike the later MPOS series that used a middle plastic case piece as their backplates, RPOS series use metal backplates but how they're affixed to the barrel plate differs between eras. Generally speaking, RPOS keyboards made by Lexmark and Maxi Switch use melted plastic rivets much like their famous buckling spring brethren. These rivets are the single largest flaw in most Model M keyboard designs as they can weaken and break with age. Such an issue can be permanently solved with a bolt or screw mod. However, XAC and XSZ made keyboards seem to use screws that make servicing the membranes easy.
As with their key-switches, RPOS keyboards have two distinct eras in their keycap designs. When RPOS was produced by Lexmark and Maxi Switch, they used high-quality PBT keycaps with any permanent key legends printed via dye sublimation. Versus the most common keycap material, ABS[8], PBT is more durable, don't degrade/yellow with age, UV or heat exposure, and will keep its texture for longer without shining[9]. Dye-sublimation is also a very durable text printing method that sinks dye material into the keycap's plastic itself, meaning there is nothing to quickly wear off as would be the case with pad-printing, silk screening, laser etching or laser etching with infill. M9s from this era usually had blue-coloured Ctrl key legends and green-coloured Alt key legends with some correspondingly coloured legends on other keys to indicate what modifier is needed to activate a secondary function from another key; usually, the Print Screen key's "SysReq" legend is coloured green and the Pause key's "Break" legend is coloured blue.
RPOS keyboards made by XAC or XSZ seem have ABS keycaps instead. In terms of permanent legend printing methods, pearl white RPOS keyboards use lasered legends whereas later grey/black verisons used pad-printed legends. Whilst the legends seem to still hold up reasonably well, they will not have anywhere close to the same 'staying power' as dye-sublimated legends.
The alphanumeric keycaps for the M9 and M11 are standard unit sizes, however, relegendable keycap stems on the M7, M7-1 and M8 can take 1-unit or 1.25-unit form. Transparent keytops for 1-unit stems can take 1-unit, 2-unit horizontal or 2-unit vertical forms - use of 2-unit relegendable keycaps require configuration from a host system utility to disable one of the two keystems' from registering its own keypress. Removing a Lexmark or Maxi Switch era RPOS keycap is easy thanks to its crosspoint mount, meaning a wire keycap puller should be sufficient. However, caution is still advised as instances of snapped stems have been observed. Reattaching them is also easy and in fact they can be substitued with Model M6 or M6-1 (most early IBM ThinkPad, Lexmark Lexbook, Apple Newton X0044, etc.) keyboard keycaps should it be desired.
XAC or XSZ era keycaps are unfortunately more difficult to remove without breaking the top of the keystem off. To remove 1-unit relegendable keycap stems:
However, it's generally not adviOther keys such as alphanumeric, modifiers and spacebar can only be safely removed by opening up the internal keyboard assembly and pushing them out from the other side of the barrel plate. To put a keycap back in, you simply push it back in with the two protrusions on the keystem's plug facing left and side relative to the keyboard. If the key doesn't press properly or stays stuck at the bottom, you should be able to rotate the keystem until it starts acting normally again.
The IBM Retail POS Keyboard with Card Reader (designated M7) is a successor to the IBM 4680 series 50-Key Modifiable Layout Keyboard. The M7 remains a 50-key keypad with a very similar layout consisting of three banks of keys with a numeric keypad taking up the center one and right one being the largest. Although instead of having dedicated "S1" and "S2" keys in the top-right area like the old 4680 keypad had, the M7 has a dedicated Ctrl key in the top-left corner. The M7 has both a key-lock and an integrated magnetic stripe reader. It was replaced by the IBM Modular 67-Key POS Keyboard in 2008[14], which would need to be fitted with an MSR and key-lock module to like-for-like replace the M7.
The IBM Retail POS Keyboard (designated M7-1) is another successor to the IBM 4680 series 50-Key Modifiable Layout Keyboard but perhaps more closely following the older keyboard's design. The M7-1 is largely the same as the M7 but lacks an MSR just like the old 4680 keypad. Otherwise, it retains the very similar layout consisting of three banks of keys with a numeric keypad taking up the center one and right one being the largest. Although instead of having dedciated "S1" and "S2" keys in the top-right area like the old 4680 keypad had, the M7-1 has a dedicated Ctrl key in the top-left corner. It too was succeeded by the IBM Modular 67-Key POS Keyboard in 2008[14], which would need to be fitted with a key-lock module to like-for-like replace the M7-1.
The IBM Retail POS Keyboard with Card Reader and Display (designated M8) is the successor to the IBM 4680 series 50-Key Modifiable Layout Keyboard and Operator Display (also known as the IBM 4680 Combined Keyboard/Display[15]). The M8 design resembles that of an enlongated M7 fitted with a tilt-adjustable 2x20 LCD screen. It too features three banks of keys with a numeric keypad taking up the center one and right one being the largest, however, the individual Ctrl key is now aligned at the bottom of the keyboard. M8s are only available with MSRs as well. It was succeeded by the IBM Modular 67-Key POS LCD Keyboard in 2011[16], which would need to be fitted with an MSR and key-lock module to like-for-like replace the M8.
The IBM Retail ANPOS Keyboard with Card Reader (designated M9) is the successor to the IBM 4680 series ANPOS Keyboard. The M9's name is usually abbreivated as simply ANPOS, but it's also known as RANPOS (Retail ANPOS)[15] or NANPOS ("New" ANPOS)[17] to differentiate it from earlier keyboards of the same name. For the most part, the M9 can feature a fairly standard Enhanced layout but features some design holdovers from the 4680 ANPOS Keyboard including 2-unit Ctrl keys and function keys segregated into two blocks of 6 keys instead of 3 blocks of 4 keys. Early M9s made by Lexmark or Maxi Switch could feature blue coloured Ctrl keys and green coloured Alt keys, but this practise was discontinued with the move to Far East based manufacturing in the 2000s. The M9 can have 116 (US English) or 117 (rest of world) keys - all M9s have an ISO-style enter key but the US English layout has a large ANSI-style shift key, whereas the rest of world layout has a small ISO-style shift key. 58 or 59 of those keys have set alphanumeric keycaps with the other 58 having relegendable-style keycaps despite many having Enhanced layout style keys already printed on them. By September 2001, the M-e based IBM PS/2 ANPOS Keyboard with Integrated Pointing Device was introduced[18] as a slight upgrade to the M9 that added a TrackPoint-like pointing stick to the keyboard's design just below the arrow keys. A USB version was also introduced around the same time but both enhancements to the like dropped the official "M9" designation despite clearly being evolutions of the same design. All three designs were succeeded by the IBM Modular ANPOS Keyboard in 2008[14], which would need to be fitted with an MSR and key-lock module to like-for-like replace the M9.
The IBM Modifiable Layout Keyboard (designated M11) is the successor to the IBM 4680 series Matrix Keyboard (P/N 76X0100). It is a 133-key matrix-style keyboard fitted inside the same chassis as the M9 and sometimes described as a "key array" in the keyboard enthusiast space. It has 6 less keys than its predecessor and the most of the layout is very different, but it typically retains a dedicated numeric keypad, now occupying the same relative position as the navigation keys on the M9. M11s can be used as an ortholinear-style alphanumeric keyboard or as a purely functional keyboard. Unlike all the other RPOS designs, the M11 never received a like-for-like MPOS replacement but can theoretically be substitued with two 67-Key MPOS Keyboards.
ASK. Admiral Shark's Keyboards original content. License/note: CC BY-NC-SA 4.0.
