I have mentioned before that my interest in computers and operating system and my general, overall geek-ness started with a fascination with cash registers, specifically the electronic point of sale systems from the 1970s. While the mechanical Sweda cash registers at the local Ames were “electronic” in the sense that they punched a tape that could be read by an IBM mainframe, the Sears in both Watertown and North Syracuse, like all the other Sears stores across the country, had one of the first electronic point of sale systems ever installed for a retailer.

I could vividly remember some details of the point of sale system used by Sears. The cash registers were made by Singer. The lettering on the cash register was in all lowercase letters, as was the tech-chic style back in the 1970s. The LED number display was large and just one line of numbers across the top of the cash register. Instead of instructional messages being spelled out or illuminated on the display, the appropriate buttons on the keyboard were lighted up with the various options at any point in a transaction. The drawer popped open when the cashier pressed total. Amount tendered entry and the associated change did not appear on the receipt, it was computed after the sale was completed. That’s one of the reasons that the cashier asked about cash/check/charge prior to ringing up the sale. This is back in the day when cashiers cared about these things. An optical “wand” was added in later years, giving the cashier the capability of reading a price tag with OCR lettering. The price was usually entered in separately.

There’s not a lot of detail about this Singer point of sale system online; over the weekend I filled in the gaps of my memory by reading old issues of “Computerworld” via Google Books. It was there that I discovered that the point of sale system was actually called the Singer Modular Data Transaction System, or Singer MDTS. Both the Singer and Friden Corporations had either merged or were working together on the project; some registers are marked Singer, some Friden and some Singer-Friden. The typical cash register in a Sears store had 2K of memory. That’s two kilobytes. To put that in perspective, it would take over 33 MILLION cash registers to provide the same amount of memory found in my iPhone 6s Plus.

My, we’ve come a long way.

As I was doing research on the Singer MDTS system, I came across an eBay auction for a press photo of one of the data terminal cash registers. Since I have a very small display of these old machines in the way of framed photos in the downstairs bathroom, I bought the photo and put it up today.


I can’t help but think that technology from this era is when technology was truly exciting. Developers had to cram a lot of software into a very small space. User expectations weren’t set yet. Technology people were blazing into unknown territory. Today’s technology, while exciting in what it can do, is predictable and quite frankly, rather boring. There’s nothing new that has really shaken up the world since the introduction of the smartphone in the mid ’00s. That’s one of the reasons for my never-ending interest in Linux (even though I primarily use Apple products) because Linux keeps me in an explorer mindset and helps my geek-ness grow.

I’d love to get my hands on one of these cash registers to see what makes it tick, but I have a hunch they’re all sitting in landfills scattered around the country. I passing through a smaller Sears store in the mid 1990s and they had one of these registers still running in the kiosk under the stairs where they copied keys. I guess it was doing what it had to do so they stuck with it.


  1. Such memories…Sears was one of the anchors at Crestwood Plaza in Crestwood, MO. Shopped there for Toughskins and Winner II shoes in the mid-70s. I recall those registers well–they stamped a 4 part carbon form with the credit card, then fed the form down the throat of the machine where it advanced up as it printed. If you paid cash, the tape on the machine was used. I remember being terribly impressed when I asked (I was maybe 10) if the register was communicating somewhere and was told that it was talking to Chicago. My grandparents lived there and it was a 6 hour drive! I could almost recall the sound it made—I remember the flashing lights underneath the keys and the 5 key had a circle of raised dots (for finger placement)

    I worked at LS Ayres in Cincinnati OH in 1986-7 which still had it’s first gen cash registers (by that time most other stores were on their 2nd gen registers). I don’t recall the vendor of those (they must have been Associated Dry Goods’ units because they were in St. Louis at Stix Baer and Fuller in the 70s). Up in your area they may have been at Sibley’s. They had a weird design where they used an old fashioned tractor-feed serialized sales check (same size whether there was one or five items–more than that it would print out a CONTINUE CONTINUE continuation to the next check). They had a single row of context sensitive keys which had labels that lit up. There were two keys to start a transaction (SALE or SINGLE ITEM SALE–telescoped some of the steps). You hit SALE, then your employee number (mine was 33459…the lead Mary’s was 3388), and ENTER, then you were given the first context sensitive option of CASH TAKE, CASH SEND, CREDIT TAKE, CREDIT SEND, BANK TAKE, BANK SEND (don’t recall the order). You hit the correct classification, then you were given your second context sensitive option around discounts (NONE, %AGE, $$ AMOUNT). You would then enter the charge account number if appropriate. For the domestics/linens department where I worked, we had department and class (for clothing and, oddly, artificial flowers, there were SKU numbers). Department 70 was sheets, 60 was towels, 80 was blankets; 85 was pillows, and so forth. In D70, class 1 was 180 count solid percale, 2 was 180 count prints, 3 was 200 count (and so on). The context sensitive was used after a line was entered for discount (you would enter either the $$ or the percentage). No memory or price look up at all. At the end of entry, you would hit the subtotal key, which brought up the next context sensitive menu (TOTAL, TAX EXEMPT, SHIP FEE, GIFT WRAP and probably some others I don’t recall). You’d enter anything else there and then hit TOTAL, when the register then would get the approval, total and finish printing the sales check. You would have the customer sign, stamp the account number then split the ticket apart (one copy stayed in department, one to sales audit and one went to customer). If there was a send, you would hand write the send information and tear off the label from the top copy and bag everything up for the Gift Wrap ladies. Ahh memories…

    Other memories…St. Louis supermarkets were somewhat late to scanning, but went with a vengeance (the big supermarkets there except for Kroger essentially went directly from NCR electromechanical to Datachecker scanning in roughly 1979–supposedly by 1980 they had the highest % of stores using scanning in the US. Kroger had the most sophisticated mechanical registers I’d ever seen–I think they were Anker or ACS or some such–they dispensed stamps, had coin dispensers, were able to separate taxable from non-taxable merchandise (in MO all food was taxed, but the federal tax on my mom’s cigarettes wasn’t–they rang in $4.99 TAX then .90 NOTAX).

    Last time I ever saw mechanical cash registers at a chain supermarket was at an old Safeway in 1988 in Albuquerque (which had the Sweda ones you’ve mentioned along with the turntable check stands in an old Marina (arch-roof) store.

    St. Louis was an early Target market (1969 or so), and also had Venture (Target clone by May Department Store Company which was based there). Target had the mechanical registers that punched the tape–I don’t recall that Venture had the tape-punching mechanical registers (but they had the 3 number department/3 number class on NCR registers). Korvette was in St. Louis as well–about 1973 they got the Sweda registers which had a clip on the front where the checker would put the bills before they put them into the drawer. Target converted to the IBM registers, and Venture converted to the registers which the department stores used, then a register with a large amber CRT

    1. Thank you for your very detailed memories here… Very fascinating. I went to Sibley’s a couple of times when I was a kid, I guess they must have normally been out of our price range, but I do remember the tractor fed sales slips with the CONTINUE CONTINUE at the bottom.

      I remember context keys lighting up on registers (other than at Sears) but I don’t remember who made the registers. We had a Barkers department store that had registers with the numeric pad arranged into two columns, 0 1, 2 3, 4 5, etc. I believe they were made by Pitney Bowes/Alpex.

      I can remember the sounds of the Singer registers at Sears as well, perhaps that was the first time I heard a dot matrix printer. I remember asking the cashier why she didn’t put a sales slip in the printer before our order, it had to do with the transaction being a cash sale vs a charge.

      I worked at Hills in the late 1980s and they had the older NCR 255s from the late 1970s; those registers had a very distinct sound to the printer. The later NCR 1255s had dot matrix printers that sounded like they were going to rattle apart.

  2. Now that you say it, I do recall the sound of the registers at Sears….they stamped the multi-part (with carbon paper) sales check for a charge sale with the Addressograph (ha! remembered that too–we used same type ones at LS Ayres) then they fed the check into the throat of the machine where it went up. I think all of the standard Associated Dry Goods stores (ADG) used that same cash register–Lord and Taylor was the exception–all of their stores used hand-written sales checks during that period–they used a credit terminal with a 10 key keypad to check credit cards and get referral numbers. St. Louis was the headquarters for MasterCharge (they still have a huge data center there and do a lot of their IT there). Also, back in the day, it was unusual for a department store to take other than their own credit card account. The first “crack” in that was American Express, which made inroads in the 80s into the department stores. Sears, Penney and Wards didn’t accept bank cards until later.

  3. Greetings,

    I was as Singer Friden Service Engineer that was trained on the MDTS and associated equipment. I installed and maintained three Sears stores in Tampa, St. Petersburg and Lakeland. I was scheduled to do a fourth in Sarasota but left the company for greener pastures before that installation began.

    The cash register terminal (MDTS) was connected to a Singer System Ten system located in the bowels of the Sears store storage room.

    The “CPU” of the terminal had three instructions, LOAD, READ and BRANCH. The architecture of the hardware included a KEYBOARD, PRINTER, 7 SEGMENT DISPLAY, CORE MEMORY (256 BYTES), COMMUNICATIONS, CPU with EPROM, ARITHMETIC LOGIC, and DRAWER (solenoid).

    The CPU would LOAD a value, key code, etc to the appropriate device, say the ARITHMETIC LOGIC, READ the result and BRANCH to the address in the program path determined by the result.

    The communications to the main frame was on a 20 mil current loop which was sufficient for the terminal positions within the main building but suffered from data loss when the Sears Auto Center was across the parking lot.

    The printer was not dot matrix but print wheel. There was also a logo stamp that was released to print on each receipt. The wheel was small and did not contain the entire alphabet. The digits 1-0, period, comma, $ and some others were on the wheel as well as an “X”. The X was important in that when the transaction was unable to be recorded on the mainframe, the printer would print a line of X’s across the journal tape. These transactions would be reentered manually by store personnel once the store closed and the journal tapes pulled.

    Invariably, the mainframe would crash whenever I wanted to go to lunch. On my way to the store cafeteria (remember those) I would here failed transactions from the terminals I passed as it sounded like a store full of crickets. Next would be the page over the PA system with the code for the system tech (me) to report to the office.

    Two interesting antidotes about these systems;

    The sales clerk entered the Sears Card number on the terminal. The terminal would transmit it to the mainframe where a current status of that card was stored. A response was sent back to the terminal as a number between 1 and 9. 1 was good credit, 2-8 were 30/60/90 days past due and other issues, 9 was a stolen card. Sears did not realize how easily a young clerk might wet her pants when facing a thief. The procedures were quickly altered to a single number other than 1 that was a code to call the business office. A manager would appear to discuss the credit problem with the customer. Often a security guard would accompany that manager.

    The Louisville, Kentucky Sears Store was the test site for the original installation. Engineers from San Leandro, CA spent weeks setting up the system and testing the software. It was a large system with 80 terminals. On the day it went live an unanticipated problem appeared. The cash drawers would not open. The terminals had never been tested with change in the drawer. The springs were not strong enough to propel the drawer out with the added weight. Those engineers scoured the town for larger springs.

  4. Thanks Tom D for the awesome details. My first job in high school was at Sears in 1977 and I trained on those registers. You brought back a lot of memories of what I experienced… especially the credit card part and the X’s (I did not even know what the X’s were when I closed the register at close).

    I remember when I trained on the register I had never seen anything like it anywhere. They were very cool, and yeah how can you forget the sound of the dot matrix printer inside writing out the receipts. I also remember the little red laser handheld lights you used to scan the special price tags that were made to be used with the registers. They had the 3 lines and you would scan each line separate… the dept line, the item line, and the price line. They had the crazy looking computer fonts. Seems like when I left about 3 years later they were in the process of changing over to some sort of big TRW (I think it was TRW) registers that had the first little monitors on them. Seas was definitely a leader in register technology back in the day… coll that you supported it.

    Anyway it was very interesting to read your comments. I never really realized how powerful Sears was back in the day, and how they dominated and created many things. Sad to see where they are today and that they will probably be gone soon.

  5. I remember going to SEARS in the early 1980’s at Eastern Hills Mall outside of Buffalo, NY. My parents were devoted shoppers of the store as many middle class people were back then. The store was huge to me at that time. I remember being fascinated by those 1970’s modern registers with there lighted keys and sounds, very futuristic. I recall coming down the escalator many Saturday afternoons and seeing the whole lower level busy with the sales people quickly keying the information into the registers. They look to have been designed to enable the user to do most of the keying without looking. I wanted to get behind the sales counter and play with them! I would love to have one of those Singers too. I remember the Sibley’s resisters too with the long receipt. When I was 16, I worked at Ames the Hills on IBM 3684s and later NCR 2152s with the May Company store divisions. Those were the days!

  6. Interesting note to Tom D’s comment – my father was one of those engineers from San Leandro. I remember him making that trip to Louisville.

    My dad was in on the design of the MDTS – the display wasn’t LED, it was neon glow blubs. He got patent for the hardware that drove the display.

    The memory was indeed 2K, and my father was kicking himself until he died because he wasted 20 bytes in the instruction set that he could have saved using math subroutines!

    A bit of clarification – Singer bought Friden in 1965, so Friden was a subsidiary.

  7. Actually there were two types of memory in the MDTS, EPROM with the instructions (2K) and Core (256 bytes) for non-volatile storage such as the department number where the register was installed, sales tax percentage, etc. The core was also used for the calculator registers (results from the arithmetic module). The use of core memory made the machine very susceptible to static discharge, think nylon stockings, leather shoe soles and carpeted sales floor.

    The keyboard was of the sliding baffle type. Each key had a code of holes in a slider that would allow the lights shined down a path to photocells. I can’t recall if it had more than four bits of data. It may have been five bits wide to accommodate all the keys.

    Those keys were backlit and the lights sequenced to show the operator what to press next (Total, SubTotal, Amt Tendered, etc.)

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